JP2001111614A - Communication method, communication system, transmitter, receiver and communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication method for communication in the unit of information consisting of a header part and a user information part where a transmitter side can transmit newly attached information without the need for revising a predetermined standard and for decreasing the capacity for the user information part. SOLUTION: The transmitter side selects an error control method to generate error control information for the user information part or the header information part depending on the attached information. A receiver side detects which of the error control methods the attached information uses among a plurality of the error control methods to detect the attached information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication method, a communication system, a transmitting device, a receiving device, and a communication device.
In particular, the present invention relates to transmission of additional information when digital data is transmitted in accordance with a defined standard.

[0002]

2. Description of the Related Art Digital data communication is often performed in units of information including a header section and a user information section, and is usually performed according to a predetermined communication format. In the header portion, additional information such as identification information of an information unit of digital data or destination information is inserted and transmitted. The additional information that can be transmitted is determined by a predetermined standard.

[0003]

By the way, in the case of performing digital data communication in the above-mentioned prescribed communication format, when a communication user wishes to define and use a unique communication mode, the communication is performed. It is necessary to transmit additional information such as mode information. This additional information is transmitted using a header section or a user information section. When such additional information is transmitted in a prescribed communication format even with one bit, the following is performed. Problem.

[0004] In the case where a header section is used, the reserved area can be used if a reserved area is prepared in the header section according to the standard, but if there is no such reserved area, a new area can be used. There is no other way than to establish a communication standard and include additional information.

When the user information section is used, it is necessary to reduce the user information by the amount of the additional information, secure a space, and insert the additional information into the space. Therefore, the capacity of user information that can be transmitted for each information unit is reduced.

In view of the above, the present invention makes it possible to transmit new additional information without having to establish a new communication standard and without reducing the amount of user information that can be transmitted for each information unit. It is an object to provide a method and a device for enabling this.

[0007]

According to a first aspect of the present invention, there is provided a communication method for performing communication in an information unit including a header section and a user information section. Including error control information on user information, on the transmission side, the error control information switches among a plurality of error control schemes according to additional information, and on the reception side, any one of the plurality of error control schemes is used. The additional information is detected by detecting whether the additional information is present.

According to the communication method according to the first aspect of the present invention, the additional information is transmitted and detected according to the type of the error control information of the error control information added to the user information in the user information section. Can be. Therefore, new additional information can be transmitted without changing the configuration of the header section and without reducing the capacity of the user information in the user information section.

[0009] The communication method according to the second aspect of the present invention provides:
In a communication method for performing communication in an information unit consisting of a header part and a user information part, the header part includes error control information on header information, and on the transmission side, the error control information is plural in accordance with additional information. And the receiving side detects the additional information by detecting which of the plurality of error control systems is used.

According to the communication method according to the second aspect of the present invention, the additional information can be transmitted and detected according to the type of the error control method of the error control information added to the header information of the header portion. it can. Therefore, new additional information can be transmitted without defining a new communication standard and without reducing the amount of user information.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Outline of Communication System of Embodiment] FIG. 2 is a block diagram showing an outline of an embodiment of a communication system according to the present invention. In the communication system of this embodiment, communication data is packetized, and packet communication is performed between the plurality of communication devices 1 connected to the packet communication network 2 via the packet communication network 2.

The communication apparatus 1 includes a transmission unit 10 including an input unit 11, a transmission data processing unit 12, and a transmission unit 13.
, Receiving unit 21, received data processing unit 22, and output unit 2
3, a control unit 30, a key operation unit 31, and a distribution unit 32.

In the transmitting unit 10, the input unit 11
The data to be transmitted is sent to the transmission data processing unit 12. In this example, the transmission data processing unit 12 packetizes data to be transmitted. Each packet has a structure including a header section and a user information section, and the header section and / or the user information section includes error control information.

In this case, the error control information generated by a different error control method according to the additional information to be transmitted accompanying the packet data is included in the packet data. It should be noted that which error control schemes are used is predetermined in this communication system.

The packet data generated by the transmission data processing unit 12 is transmitted to the packet communication network 2 through the transmission unit 13 and the distribution unit 32.

On the other hand, in the receiving unit 20, the receiving unit 2
1 receives the packet data transmitted through the packet communication network 2 via the distribution unit 32 and transmits the packet data to the reception data processing unit 22.

The received data processing section 22 separates the received packet data into a header section and a user information section, performs predetermined processing on the separated user information, and outputs the processed user information through the output section 23.

The control unit 30 controls the entire communication device 1. As will be described later in detail, the control unit 30 identifies which error control method is used for the error control information included in the packet data, detects additional information, and detects additional information. The reception data processing unit 22 is controlled to perform the corresponding reception data processing.

The key operation unit 31 includes a plurality of keys for starting transmission / reception, inputting a destination at the time of transmission, and the like. The control unit 30 detects which of the keys has been operated by the user.

Several embodiments of examples of additional information to be transmitted and a mode of transmitting the additional information in the communication system having the above-described configuration will be described below.

[First Embodiment of Transmission of Additional Information] In the first embodiment, user information for packet communication is information (real-time data, such as audio information and image information) that requires real-time properties. ) And other information that does not require real-time properties (non-real-time data), and which type of user information is transmitted as additional information.

In the first embodiment, an error detection code is added as error control information to user information in units of packets, and two types of error detection codes are generated as this error detection code. Prepare a method,
The error detection code generation method is made different between when the user information to be subjected to packet communication is real-time data and when it is non-real-time data.

[Transmission Data Processing Unit of First Embodiment]
FIG. 3 is a configuration example of the transmission data processing unit 12 in the case of the first embodiment, and includes a header generation unit 41, a user data transmission unit generation unit 42, and a transmission data generation unit 43.
, Two error control information generators 44A and 44B, and a switch circuit 45 for selecting which of the two error control information generators 44A and 44B to use. These two error control information generation units 44A,
44B, in this example, as described above, are two different types of error detection code generation systems and are two types of error detection codes EDC
(A) and EDC (B) are generated.

Under the control of the control unit 30, the header generation unit 41 generates a header portion HD including predetermined information as shown in FIG. The generated information of the header section is supplied to the transmission data generation section 43.

The user data transmission unit generation unit 42 extracts, from the data from the input unit 11, transmission unit user data of a predetermined number of bits or bytes as constituting a user information part of a packet, and The error detection code for the data is sent to the error control information generator 44.
A or 44B, and adds the generated error detection code EDC (A) or EDC (B) to the user data to generate data of the user information part of the packet.

In this case, the control unit 30 identifies whether the data from the input unit 11 is real-time data or non-real-time data, and switches the switch circuit 45.
, And the error control information generation unit 44A or 44B
Is controlled.

The discrimination between the real-time data and the non-real-time data in the control unit 30 is as follows.
For example, the type of the transmission data of the user through the key operation unit 31 is determined and performed. Note that a circuit for determining whether the data from the input unit 11 is real-time data or non-real-time data may be provided, and the control unit 30 may monitor the determination output.

In this example, when the data from the input unit 11 is real-time data, the error control information generation unit 44A is selected, an error detection code EDC (A) is generated for the transmission unit user data, and the input unit When the data from 11 is non-real-time data, the error control information generation unit 44B is selected, and the switch circuit 45 is switched and controlled so that the error detection code EDC (B) is generated for the transmission unit user data. You.

The user data transmission unit generation unit 42 sends the extracted transmission unit user data to the error control information generation unit 44A or 44B switched and selected by the switch circuit 45. Upon receiving the transmission unit user data, the error control information generation unit 44A or 44B uses the error detection code generation method to generate the error detection code EDC (A) or EDC for the transmission unit user data.
(B) is generated.

The user data transmission unit generator 42 adds the generated error detection code to the transmission unit user data to generate a user information part of the packet. And
The generated user information section is sent to the transmission data generation section 43.

The transmission data generation unit 43 includes the header generation unit 4
1 is combined with the information of the user information section from the user data transmission unit generation section,
To send out.

As a result, the transmission data generation unit 43
When the user information is real-time data, as shown in FIG. 4A, packet data in which the error detection code EDC (A) generated by the error control information generation unit 44A is included in the user information part is transmitted. Also, when the user information is non-real-time data, FIG.
As shown in (1), packet data in which the error detection code EDC (B) generated by the error control information generation unit 44B is included in the user information section is transmitted.

The processing in the transmission data processing unit 12 described above can also be realized by software. FIG. 1 is a flowchart showing a transmission processing routine in that case.

That is, first, a header section HD is generated (step S101), and then it is determined whether or not the input data is real-time data (step S10).
2). If the data is real-time data, error control information of user information, in this example, an error detection code EDC (A) is generated by the error control method A and added to the user information (step S103). If the data is non-real-time data, the error control information of the user information according to the error control method B, in this example, the error detection code EDC (B)
Is generated and added to the user information (step S10).
4).

Step S103 or step S10
From step 4, the process proceeds to step S105, where the header section HD and the user information section of the packet are transmitted, and the transmission processing routine of FIG. 1 ends.

[Received Data Processing Unit of First Embodiment]
Next, the reception data processing unit 2 in the communication device 1 that receives the data transmitted as the packet data as described above.
FIG. 5 shows a configuration example of No. 2.

That is, in this example, the reception data processing unit 22 includes a header detection unit 51 and a user information extraction unit 52
, Two error control units 53A and 53B, a selector unit 54, and a data processing unit 55.

The data received from the receiving section 21 is supplied to a header detecting section 51, where the header section is extracted, and the extracted header section is supplied to the control section 30. The control unit 30 uses the information in the header for subsequent processing. The received data is
Subsequently, the information is supplied to the user information extraction unit 52, and the user information is extracted. The extracted user information is supplied to two error control units 53A and 53B, respectively.

Each of the two error control units 53A and 53B performs error control on user information according to each error control method. In this example, the error control unit 5
3A performs error detection when the error detection code is EDC (A), and the error control unit 53B performs error detection when the error detection code is EDC (A).
Error detection for DC (B) is performed.

The two error controllers 53A and 53A
Each of 3B supplies the result of the error detection to the control unit 30. The control unit 30 controls selection of the selector unit 54 so as to select the error control unit that has been detected as having no error from the error detection result input thereto.

At this time, the control unit 30 detects the additional information depending on which of the error control units 53A and 53B determines that there is no error. In the case of this example, when the error control unit 53A determines that there is no error, the user information is determined to be real-time data, and
When the error control unit 53B determines that there is no error,
The user information is determined to be non-real-time data.

When both of the results of the error detection by the error control units 53A and 53B are determined to have an error,
The data processing unit 55 performs processing at the time of error for the user information at that time. For example, the incorrect user information is not used (discarded).

The error control unit 53A determines that there is no error, and the user information obtained from the selector unit 54 is supplied to the data processing unit 55, and under the control of the control unit 30, the user information at the time of reception of the real-time data is received. Processing is performed. Also,
The error control unit 53B determines that there is no error, and the user information obtained from the selector unit 54 is supplied to the data processing unit 55, and the processing at the time of receiving the non-real-time data is controlled by the control unit 30. Done.

In this case, when the control unit 30 determines that the user information is real-time data based on the additional information, the control unit 30 controls the data processing unit 55 to perform processing at the time of receiving the real-time data. Further, when it is determined from the additional information that the user information is non-real-time data, the data processing unit 55 controls to perform a process at the time of receiving the non-real-time data.

The above-described processing in the reception data processing unit 22 can also be realized by software. FIG. 6 is a flowchart showing a reception processing routine in that case.

That is, first, the header of the received packet data is detected (step S201), and user information is extracted (step S202). Next, the extracted user information is verified by the error control method A. That is, in this example, error detection is performed when the error detection code is EDC (A) (step S203). Then, the result of the error detection is determined (step S204).

As a result of the determination, when it is determined that there is no error, it is determined that the additional information indicates that the user information is real-time data, and a process at the time of receiving the real-time data is performed (step S1). S205).

As a result of the determination in step S204,
When it is determined that there is an error, the user information extracted in step S202 is verified by the error control method B. That is, in this example, the error detection code is EDC
Error detection is performed for (B) (step S20)
6). Then, the error detection result is determined (step S207).

As a result of the determination, when it is determined that there is no error, it is determined that the additional information indicates that the user information is non-real-time data, and a process at the time of receiving the non-real-time data is performed. (Step S20
8).

As a result of the determination in step S207,
When it is determined that there is an error, a process at the time of a reception error is performed on the user information extracted in step S202 (step S209). Thus, the reception processing routine of FIG. 6 ends.

As described above, according to the first embodiment, by using a plurality of types of error control information such as an error detection code added to user information in a packet unit, the error control The type of information can be transmitted as additional information. For this reason, without changing the header part where addition of additional information is difficult in the standard, and
The additional information can be transmitted without reducing the capacity of the user information in the user information section.

The error control information is not limited to the error detection code, but may be an error detection and correction code. Also,
The number of types of error control information to be used is not limited to two as in the above example, but may be three or more to increase the amount of additional information.

[Second Embodiment] In the first embodiment, the case where error control information is transmitted for user information for each packet is described. In some cases, the error control information is not transmitted for the packet-based user information.

For example, the switching system required for the next-generation network is to cope with an increase in information transmission speed, to have a variable transmission speed function, to be able to transmit multimedia information, and the like. ATM (Asynchronous Transfer Mode)
Although a switching system is provided, communication using ATM cells in the case of the ATM system corresponds to the above-described case.

In the ATM system, information sent from the transmitting side to the receiving side is divided into 48 bytes, a 5-byte header is added thereto, and high-speed transmission is performed in units of 53-byte fixed-length ATM cells. . The header contains information for call identification and information for forming a communication path to the other party. Based on the information in the header, ATM cells are exchanged at high speed by an ATM switch having a hardware configuration. Is done.

On the receiving side, the information of the header of the received ATM cell is confirmed, the data in the unit of ATM cell is connected, and the original information is assembled.

FIG. 7 shows the structure of the ATM cell in the case of a UNI (User Network Interface).
That is, the ATM cell includes a 5-byte header section HD,
It consists of a 48-byte user information section. Header part HD
Are GFC (Generic Flow Control), VPI (Virtual Path Identifier), VCI (Virtual Channel Identifier), PT (Payload Type; Payload
It includes a type (indicating the type of 48-byte user information), a CLP (Cell Loss Priority), and a HEC (Header Error Control; header error control information).

The VPI and VCI are ATM routing fields, that is, fields for determining what communication path the cell selects. UNI (User
Network Interface), 1 byte for VPI, VC
Two bytes are allocated to I. VCI is a virtual channel number for call identification, and VPI is an identifier for specifying a communication path.

In the ATM switching network, the VPI and VCI are allocated and set between the originating terminal, the originating exchange, the transit exchange, the destination exchange, and the destination terminal, thereby forming a virtual path. Communication is performed.

Incidentally, the ATM standard protocol has a hierarchical structure, and is handled uniformly by ATM cells.
AAL (ATM adaptation layer) for matching / adjusting 8-byte user information with data units of various higher-level applications such as voice and data, and adding a 5-byte ATM cell header to 48-byte user information An ATM layer that processes ATM cells, and an SDH (Synchronous Digital Hierar
chy) and a physical layer for generating a frame.

The AAL defines several types as protocols for realizing various services. The protocol format of AAL type 5 is as shown in FIG.

That is, the AAL type 5 CPCS (Co
mmon Part Convergence Sublayer)
It is as shown in FIG. That is, a padding PAD for adjusting the CPCS frame to be an integral multiple of 48 bytes is added after the user information, and thereafter, a display between CPCS users for equivalently transferring information used in an upper layer. CPCS-UU,
The common part type display CPI and the payload length Length indicating the user information length are added. Finally, as an error detection code for performing error detection of the entire CPCS frame, 4
A byte CRC code (referred to as CRC-32) is added.

Then, as shown in FIG. 8, the CPCS frame is divided in units of 48 bytes, and the information in units of 48 bytes is used as user information and a 5-byte header is added to form an ATM cell. To

In the second embodiment, a plurality of methods for generating the error detection code CRC-32 of the CPCS frame are prepared, whereby the additional information is transmitted. For example, as shown in FIGS.
-32 (A) and CRC-32 (B) are prepared to transmit 1-bit additional information. Also in the case of the second embodiment, the additional information indicates the communication mode A for transmitting real-time data or the communication mode B for transmitting non-real-time data as user information.

In this example, both the CRC-32 (A) and the CRC-32 (B) use the generator polynomial conventionally defined in the ATM, but try to transmit the value calculated by this polynomial to the value. By adding different values according to the additional information to be added, CRC-3
2 (A) and CRC-32 (B).

That is, for the entire CPCS frame, the generator polynomial X32 + X26 + X23 + X22 + X16 + X12 + X11 + X10 + X
Calculate CRC-32 using 8 + X7 + X5 + X4 + X2 + X + 1. Then, in the case of the communication mode A, 0 is added to the calculation result and CR is added.
C-32 (A) is generated, and in the case of the communication mode B, CRC-32 (B) is generated by adding, for example, “00000010” to the value of CRC-32. Then, the generated CRC-32 (A) or CRC-32 (B)
In the CRC field of the CPCS frame.
Therefore, CRC-32 (A) is equivalent to the conventional CRC-3.
2 is generated in exactly the same manner as in the case of FIG.

On the receiving side, the CP including the CRC field
CRC-32 is calculated for the entire CS frame by applying the same generator polynomial as at the time of transmission. If the result is 0, it is determined that the communication mode is the communication mode A. When the calculation result of CRC-32 does not become 0, after adding “00000010” to the value of the CRC field,
Apply CR to the entire generator
C is calculated, and if the result becomes 0, it is determined that the communication mode is B.

[Transmission Data Processing Unit of Second Embodiment]
FIG. 10 is a configuration example of the transmission data processing unit 12 in the case of the second embodiment. Transmission data processing unit 1 of this example
2, a header generation unit 41, a user data transmission unit generation unit 42, and a transmission data generation unit 43
However, the user data transmission unit generation unit 42
Only the user information in units of 8 bytes is cut out, and no error control information is generated and added.

In the transmission data processing unit 12 in the example of FIG. 10, a protocol data unit generation unit 61 is provided in a stage preceding the user data transmission unit generation unit 42. Switch circuit 64
, Two error control information generating units 62 and 63 are connected. In the case of this example, the error control information generation unit 62
Generates a CRC-32 (A), and the error control information generating unit 63 generates a CRC-32 (B).

The header generation section 41 generates an ATM header section under the control of the control section 30, and supplies information of the generated header section to the transmission data generation section 43.

The protocol / data unit generating unit 61
The PCS frame is generated, and information such as the padding PAD described above is added to the user information from the input unit 11. Further, using either the error control information generation unit 62 or the error control information generation unit 63, the error detection code CRC-32 (A) or the CR-32 (A) for the CPCS frame is used.
Generate C-32 (B) and complete the CPCS frame.

In this case, the control unit 30 identifies whether the data from the input unit 11 is real-time data or non-real-time data, and
Is switched to control which of the error control information generator 62 and the error control information generator 63 is used.

The identification of whether the data is real-time data or non-real-time data in the control unit 30 is as follows.
For example, the type of the transmission data of the user through the key operation unit 31 is determined and performed. Note that a circuit for determining whether the data from the input unit 11 is real-time data or non-real-time data may be provided, and the control unit 30 may monitor the determination output.

In this example, when the data from input section 11 is non-real-time data, error control information generation section 62 is selected, and when the data from input section 11 is real-time data, error control information generation section 62 is selected. Part 6
The switching of the switch circuit 64 is controlled so that 3 is selected.

The protocol / data unit generation unit 61 uses one of the error control information generation units 62 and 63 switched and selected by the switch circuit 64 and executes the error detection code CRC-
32 (A) or CRC-32 (B),
Generate a CS frame.

The user data transmission unit generation unit 42
As shown in FIG.
The data is sent to the transmission data generation unit 43 in units of 8 bytes. The transmission data generation unit 43 generates an ATM cell by combining the 5-byte ATM header from the header generation unit 41 and the 48-byte data from the user data transmission unit generation unit, and sends it to the transmission unit 13. .

The processing in the transmission data processing unit 12 described above can be realized by software. FIG. 11 is a flowchart showing a transmission processing routine in that case.

That is, first, it is determined whether or not the input data is real-time data (step S30).
1) If it is determined that the data is non-real-time data, CRC-32 (A) is used as an error detection code and CPC
An S frame is generated (Step S302). If it is determined that the data is real-time data, the CRC
A CPCS frame is generated using -32 (B) as an error detection code (step S303).

Next, an ATM header is generated (step S
304), the user information part of the ATM cell is generated by dividing the CPCS frame every 48 bytes (step S).
305). Then, an ATM header and a user information section are transmitted as ATM cells (step S
306).

[Received Data Processing Unit of Second Embodiment]
Next, the reception data processing unit 2 in the communication device 1 that receives the data transmitted as the packet data as described above.
FIG. 12 shows a configuration example of No. 2.

That is, in this example, the received data processing unit 22 includes a header detection unit 51 and a user information extraction unit 52
, A protocol / data restoration unit 71, two error control units 72A and 72B, a switch circuit 73, and a data processing unit 55. The error control unit 72A is an error detection unit when the error detection code is CRC-32 (A), and the error control unit 72B is
The error detection unit in the case of (B).

The data received from the receiving section 21 is supplied to the header detecting section 51, the header section is extracted, and the extracted header section is supplied to the control section 30. The control unit 30 uses the information in the header for subsequent processing. The received data is
Subsequently, the information is supplied to the user information extraction unit 52, and the user information is extracted. The extracted user information is
The data is supplied to the data restoration unit 71, and the CPCS frame is restored.

The switch circuit 73 is, for example, initially connected to the error control section 72A, and the information of the CPCS frame is transmitted to the error control section 7 through the switch circuit 73.
2A. The error control unit 72A calculates the CRC-32 using the generator polynomial described above, and supplies a result indicating whether or not the calculation result is “0” to the control unit 30. When the calculation result in the error control unit 72A is “0”, the control unit 30 determines that the communication mode is the communication mode A, and recognizes that the user information is non-real-time data,
The switch circuit 73 remains on the error control unit 72A side,
The data processing unit 55 controls so as to perform processing when receiving non-real-time data.

When the calculation result of error control section 72A is not "0", control section 30 switches switch circuit 73 to error control section 72B. Then, the error control unit 7
2B adds “00000010” to the value of the CRC field of the CPCS frame, calculates the CRC by applying the same generator polynomial to the entire CPCS frame, and determines whether the calculation result is “0”. The result is supplied to the control unit 30.

When the result of the calculation by the error control section 72B is "0", the control section 30 determines that the communication mode is the communication mode B, recognizes that the user information is real-time data, and sets the switch circuit. 73 is an error control unit 72B
On the other hand, the data processing unit 55 controls so as to perform a process when receiving real-time data.

It is to be noted that, when both of the results of the error detection by the error control units 72A and 72B are determined to have an error,
Under the control of the control unit 30, the data processing unit 55 performs an error process for the user information at that time. For example, the incorrect user information is not used.

The above-described processing in the reception data processing unit 22 can also be realized by software. FIG. 13 is a flowchart showing a reception processing routine in that case.

First, the header of the received ATM cell is detected (step S401), and the user information of the ATM cell is extracted (step S402). Next, a CPCS frame is generated from the extracted user information (step S403). Then, the CPCS frame is verified by the error control method A. That is, in this example, error detection is performed by a method using the error detection code CRC-32 (A) (step S404). Then, the error detection result is determined (step S405).

As a result of the determination, when it is determined that there is no error, it is determined that the additional information indicates that the user information of the CPCS frame is non-real-time data. Processing is performed (step S406).

Also, as a result of the determination in step S405,
When it is determined that there is an error, the CPCS frame restored in step S403 is verified by the error control method B. That is, in this example, the error detection code C
Perform error detection using RC-32 (B) (step S
407). Then, the result of the error detection is determined (step S408).

As a result of the determination, when it is determined that there is no error, the additional information is determined to indicate that the user information of the CPCS frame is real-time data, and the processing at the time of receiving the real-time data is performed. Perform (Step S409).

Further, as a result of the determination in step S408,
If it is determined that there is an error, the reception error processing is performed on the user information of the CPCS frame restored in step S403 (step S410). Above,
The reception processing routine of FIG. 13 ends.

As described above, according to the second embodiment, the header and the user information of the ATM cell are added to the protocol data in the AAL layer above the ATM layer without any change. By using a plurality of types of error control information such as error detection codes, the type of the error control information can be transmitted as additional information. For this reason, the additional information can be transmitted without making any change in the ATM standard and without reducing the capacity of the user information in the protocol data section.

In the above example, by changing the constant value added to CRC-32 of the error detection code, 3
Since more than one type of error control method can be set,
The additional information that can be transmitted can be increased.

Further, it goes without saying that the second embodiment is not limited to the packet transmission of the ATM system. The error control information added to the protocol data is not limited to the error detection code, but may be an error detection and correction code.

It goes without saying that the additional information to be transmitted is not limited to the information on the presence or absence of the real-time property as described above. For example, if the protocol data is IP
Information indicating whether or not the information is packet information can be transmitted as additional information.

[Third Embodiment] In the above embodiment, a plurality of types of error control systems are prepared as error control information for user information, and the type of the error control system is used as additional information. Although transmission is performed, when error control information is included in a header portion as in the above-described ATM system, the error control information in the header portion is
In the same manner as described above, it can be used for transmitting additional information.

When the error control information in the header is used, as described above, additional information relating to the nature of the user information such as whether or not the user information following the header is real-time and whether or not the packet is an IP packet is added. Not only can it be transmitted, but also the data size (data amount) of user information per packet can be easily transmitted as additional information.

The third embodiment is an example in which information indicating the data size of user information is transmitted as additional information using error control information on header information.
In the third embodiment described below, the data size of the user information is two types, for example, one is 48 bytes and the other is 128 bytes. The configuration of the header section is the same as that of the second embodiment, that is, the header section of the ATM cell, and the header error control information HEC when the size of the user information is 48 bytes.
Is generated equal to that of a normal ATM cell. Therefore, when the user information is 48 bytes, it has exactly the same structure as the ATM cell.

Further, in this example, when the information to be transmitted as the CPCS frame is an IP packet, the data size of the user information is set to, for example, 128 bytes larger than 48 bytes of the ATM cell. An ATM cell is generated and transmitted.

[Transmission Data Processing Unit of Third Embodiment]
FIG. 14 shows a configuration example of the transmission data processing unit 13 in the third embodiment. The difference from the transmission data processing unit 13 in the second embodiment is that a plurality of error The control information generation unit is provided not for protocol data but for header information, and the data size of user information per transmission packet depending on whether the transmission data is an IP packet or not. This is the point that makes

That is, the transmission data processing unit 12 of this example
Is the protocol / data unit generation unit 61 in the case of FIG.
A protocol / data unit generation unit 81 having functions of an error control information generation unit 62, a user data transmission unit generation unit 82, a transmission data generation unit 43, and a header generation unit 83
And two header error control data generators 84 and 85 for generating error control information for the header.
And a switch circuit 86 for selecting any one of the header error control data generators 84 and 85.

In this example, when the input data is not an IP packet, the protocol / data unit generation unit 81
The padding PAD of the CPCS frame is such that the CPCS frame is an integral multiple of 48 bytes,
When input data is an IP packet, padding PA
Let D be such that the CPCS frame is an integer multiple of 128 bytes.

The user data transmission unit generation section 82
Extracts user information in units of 48 bytes for data other than IP packets from the data from the protocol / data unit generation unit 81, and extracts user information in units of 128 bytes for IP packets.

One of the two header error control data generators 84 and 85 generates error control information HEC (A) according to the same error control information generation method as error control information HEC defined in the ATM system. The other is AT
The error control information HEC is different from the error control information HEC defined in the M method.
(B) is generated.

More specifically, in the case of this example, the header error control data generators 84 and 85 use a generator polynomial conventionally defined in ATM, but try to transmit a value calculated by this polynomial. By adding different values according to the additional information, the HEC
(A) and HEC (B) are generated.

That is, the header error control data generator 8
4 considers a 32-bit ATM cell header (HEC field is not included) and 31-order polynomial, this X ⁸
And modulo 2 generating polynomial X ⁸ + X ² + X + 1, add 0, and add “010101” to the result.
01 ”is generated as HEC (A). This header error control data HEC (A) is the same as the header error control information HEC of the conventional ATM cell header because the header error control data HEC of the conventional ATM cell header is simply added with 0. .

On the other hand, header error control data generation section 85
Considers a 32-bit ATM cell header (not including the HEC field) as a 31st-order polynomial, multiplies it by X ⁸ , divides it by a modulo-2 generator polynomial X ⁸ + X ² + X + 1, and obtains a constant value corresponding to additional information. "0000001
0 is added, and a value obtained by adding “01010101” to this is generated as HEC (B).

The control unit 30 identifies whether the data from the input unit 11 is an IP packet or not, and
The switch circuit 86 is switched to control which of the header error control data generators 84 and 85 is used.

Whether the input data is an IP packet or other data in the control unit 30 is determined by, for example, discriminating a user's type input operation of transmission data through the key operation unit 31 or the like.

In this example, the data from the input unit 11 is I
When the packet is not P packet data, the header error control data generator 84 is selected, and when the packet is an IP packet from the input unit 11, the switch circuit 86 is switched so that the header error control data generator 63 is selected. .

In the above configuration, the key operation unit 3
When data that is not an IP packet is selected as the transmission data in step 1, the data is formed into a CPCS frame structure by the protocol / data unit generation unit 81, and then supplied to the user data transmission unit generation unit 82, and the control unit 30 In response to the control instruction from, it is cut out as user data in units of 48 bytes and supplied to the transmission data generation unit 43.

At this time, the switch circuit 86 is switched by the control unit 30 so as to select the header error control data generation unit 84. The header generation unit 83 includes the control unit 30
Under the control of, the header error control data generation unit 84 generates the header error control data HEC (A) as described above using the header error control data generation unit 84, and sends it to the transmission data generation unit 43.

The transmission data generation unit 43 includes the header generation unit 8
15 (A) by combining a 5-byte packet header containing the header error control data HEC (A) from the H.3 and the 48-byte data from the user data transmission unit generation unit.
A packet (ATM cell) as shown in FIG.

When an IP packet is selected as transmission data by the key operation unit 31, the IP packet data is transmitted to the protocol / data unit
After having the structure of the PCS frame, it is supplied to the user data transmission unit generation unit 82, cut out as 128-byte unit user information by the control instruction from the control unit 30, and supplied to the transmission data generation unit 43.

At this time, the switch circuit 86 is switched by the control unit 30 so as to select the header error control data generation unit 85. The header generation unit 83 includes the control unit 30
Under the control of, header information is generated, and the header error control data generation unit 85 generates the header error control data HEC (B) as described above, and sends it to the transmission data generation unit 43.

The transmission data generation unit 43 includes the header generation unit 8
5 including header error control data HEC (B) from 3
By combining the byte packet header and the 128-byte data from the user data transmission unit generation unit, FIG.
The packet data as shown in FIG.
3

The processing in the transmission data processing unit 12 described above can also be realized by software. FIG. 11 is a flowchart showing a transmission processing routine in that case.

That is, first, 5-byte packet header information (excluding the HEC field) is created (step S501). Next, it is determined whether or not the input data is an IP packet (step S502). If it is determined that the input data is an IP packet, error control information HEC (B) for the created header information is generated (step S502). S
503).

Then, the packet length is set to 133 bytes, and the CPCS frame including the IP packet is set to 128 bytes.
User information is divided for each byte (step S5
04). Then, the packet header and the 128-byte user information are transmitted as one packet (step S505).

If it is determined that the input data is not an IP packet, error control information HEC (A) for the created header information is generated (step S50).
6). Then, the packet length is set to 53 bytes, and I
The CPCS frame including the P packet is divided into 48 bytes for user information (step S507). Then, the packet header and the 48-byte user information are transmitted as one packet (step S).
508).

[Received Data Processing Unit of Third Embodiment]
Next, the reception data processing unit 2 in the communication device 1 that receives the data transmitted as the packet data as described above.
FIG. 17 shows a configuration example of No. 2.

That is, in this example, the reception data processing unit 22 includes a header detection unit 91 and a user information extraction unit 92
, A protocol / data restoring unit 93 and a data processing unit 9
4, two header error control units 95A and 95B,
And a switch circuit 96. Header error control unit 95A
Is an error detection unit using the header error control information HEC (A), and the header error control unit 95B is an error detection unit using the header error control information HEC (B).

The received data from the receiving unit 21 is supplied to a header detecting unit 91, the header part is extracted, and the error detection of the header information is performed using two header error control units 95A or 95B. At this time, the switch circuit 96
Is initially connected to the header error control section 95A, and performs error detection using the header error control information HEC (A). Then, the error detection result is sent to the control unit 30. At this time, when the value of the error detection result is “0”, the control unit 30 determines that the user information is not IP packet data but the user information per packet is 48 bytes.

When the value of the error detection result using the header error control information HEC (A) is not “0” and an error is detected, the switch circuit 96 switches the header error control section 95
Switched to B side, header error control information HEC (B)
Error detection is performed using. Then, the error detection result is sent to the control unit 30. At this time, when the value of the error detection result is “0”, the control unit 30 determines that the user information is the IP packet data, and determines that the user information per packet is 128 bytes.

Further, header error control sections 95A and 95B
If any of the detection results is not “0” and is determined to be incorrect, the control unit 30 controls to discard the information of the packet.

In the header detecting section 91, the header error control section 9
The data determined to be error-free in one of 5A and 95B is sent to the user data transmission unit extraction unit 92. In response to the control instruction from the control unit 30, the user data transmission unit extraction unit 92 extracts user information in units of 128 bytes when the received data is an IP packet.
If the packet is other than an IP packet, user information in 48-byte units is extracted. The extracted information is sent to the protocol / data restoration unit 93.

When the received data is an IP packet, the protocol / data restoring unit 93 generates a CPCS frame by combining user information in units of 128 bytes when the received data is an IP packet.
Send to When the received data is not an IP packet, the CPCS frame is generated by collecting user information in units of 48 bytes and sent to the data processing unit 94.

Data processing section 94 receives a control instruction from control section 30, and performs processing of the IP packet when the received data is an IP packet. Performs reception processing.

The above-described processing in the reception data processing unit 22 can be realized by software. FIG. 18 is a flowchart showing a reception processing routine in that case.

That is, first, the header of the received packet data is detected (step S601), and the header information is verified by the header error control method A. That is, error detection is performed by the method of the header error control information HEC (A) (step S602). Then, the result of the error detection is determined (step S603).

As a result of the determination, when it is determined that there is no error, it is determined that the additional information indicates that the user information is IP packet data, and the packet length is set to 13
User information is extracted as 3 bytes (step S60)
4), perform processing at the time of receiving the IP packet (step S6)
05).

Further, as a result of the determination in step S603,
When it is determined that there is an error, the header extracted in step S601 is verified by the error control method B. That is, in this example, the header error control information HEC
Error detection is performed by the method using (B) (step S
606). Then, the result of the error detection is determined (step S607).

As a result of the determination, when it is determined that there is no error, it is determined that the additional information indicates that the user information is not an IP packet, and the packet length is 53 bytes to extract the user information (step S608), the processing at the time of receiving the non-IP packet is performed (step S60)
9).

Further, as a result of the determination in step S607,
If it is determined that there is an error, processing for a reception error is performed on the information of the received packet (step S).
610). Thus, the reception processing routine of FIG. 18 ends.

As described above, according to the third embodiment, by using a plurality of types of error control information such as an error detection code added to the header of a packet, Can be transmitted as additional information. Therefore, the additional information can be transmitted without making any change in the standard.

Further, by using the error control information in the header part, it is possible to transmit additional information indicating the data size of the user information following the header part. Can be newly set without changing the packet size.

In the above example, three or more types of error control systems can be set by changing the fixed value added to the header error control information HEC, so that the additional information that can be transmitted is increased. Can be.

Further, it goes without saying that the third embodiment is not limited to the packet transmission of the ATM system. The error control information added to the header is not limited to the error detection code, but may be an error detection and correction code.

As the additional information, in addition to the packet size as in the above example, information on the presence / absence of real-time capability of the user information as in the above example, information as to whether or not the packet is an IP packet, etc. Various things can be transmitted.

Further, the one for transmitting error control information on the header information includes a packet header having a structure as shown in FIG. 19 (in FIG. 19, the error control information is a header checksum) in addition to the ATM cell. There are various types such as IP packets, and the third embodiment is applicable to all of them.

[Other Embodiments] The first embodiment described above
In the third embodiment, the additional information is transmitted by using the error control information of either the user information or the header information. However, the error control information is added to the user information and the header information. In such a case, it is also possible to transmit a plurality of different pieces of additional information using both of them.

Further, a mode in which the second embodiment and the third embodiment are combined can be realized.

In the above description, each embodiment has been described by taking the case of packet communication as an example. However, it goes without saying that the present invention is not limited to the case of packet communication. .

[0145]

As described above, according to the present invention, additional information can be transmitted without making any change in the communication standard and without reducing the amount of user information.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a main part of a transmission-side process in a communication method according to a first embodiment of the present invention.

FIG. 2 is a block diagram for explaining an outline of a communication system according to the present invention.

FIG. 3 is a block diagram showing a configuration example of a transmission data processing unit in the case of the first embodiment of the communication method according to the present invention.

FIG. 4 is a diagram for explaining a first embodiment of a communication method according to the present invention.

FIG. 5 is a block diagram illustrating a configuration example of a reception data processing unit in the case of the first embodiment of the communication method according to the present invention;

FIG. 6 is a flowchart for explaining a main part of a receiving-side process of the first embodiment of the communication method according to the present invention;

FIG. 7 is a diagram for explaining the structure of an ATM cell.

FIG. 8 is an explanatory diagram of an AAL type 5 protocol format of ATM.

FIG. 9 is a diagram illustrating a main part of a second embodiment of the communication method according to the present invention.

FIG. 10 is a block diagram illustrating a configuration example of a transmission data processing unit in the case of a second embodiment of the communication method according to the present invention.

FIG. 11 is a flowchart for explaining a main part of a transmission-side process according to a second embodiment of the communication method according to the present invention;

FIG. 12 is a block diagram illustrating a configuration example of a reception data processing unit in a case of a second embodiment of the communication method according to the present invention;

FIG. 13 is a flowchart for explaining a main part of a receiving-side process according to the second embodiment of the communication method according to the present invention;

FIG. 14 is a block diagram illustrating a configuration example of a transmission data processing unit in the case of a third embodiment of the communication method according to the present invention.

FIG. 15 is a diagram for explaining a main part of a third embodiment of the communication method according to the present invention.

FIG. 16 is a flowchart for explaining a main part of a transmission-side process of a third embodiment of the communication method according to the present invention.

FIG. 17 is a block diagram illustrating a configuration example of a reception data processing unit in a case of a third embodiment of the communication method according to the present invention.

FIG. 18 is a flowchart for explaining a main part of a receiving-side process in a third embodiment of the communication method according to the present invention.

FIG. 19 is a diagram showing a structure of a header of an IP packet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication device, 2 ... Packet communication network, 12 ... Transmission data processing part, 22 ... Reception data processing part, 30 ... Control part, 31
.., Key operation unit, 41, header generation unit, 42, user transmission unit generation unit, 43, transmission data generation unit, 44A, 44B
... Error detection code generator, 45, 64 ... Switch circuit, 5
1 ... Header detector, 52 ... User information extractor, 53A,
53B: Error control unit, 54: Selector unit, 55: Data processing unit, 61: Protocol / data unit generation unit, 62,
63: error control information generator, 72A, 72B: error controller, 73: switch circuit, 81: protocol unit data generator, 82: user data transmission unit generator, 83: header generator, 84, 85: header error Control data generation unit, 86: switch circuit, 91: header detection unit, 92:
User data transmission unit extraction unit, 93: protocol / data restoration unit, 94: data processing unit, 95A, 95B: header error control unit, 96: switch circuit

Claims (48)

[Claims] In a communication method for transmitting predetermined information by adding error control information, the transmission side switches a plurality of error control systems according to the additional information to be transmitted, and A communication method, wherein the side detects the additional information by detecting which of the plurality of error control systems is used. 2. A communication system in which predetermined information is transmitted by adding error control information, wherein a transmitting side device includes a plurality of error control information generating means for generating error control information of different systems, Selecting means for selecting one of the plurality of error control information generating sections in accordance with the additional information to be performed; and Information transmitting means for generating control information and transmitting the generated error control information together with the predetermined information, wherein the receiving-side apparatus comprises: A communication system comprising: an additional information identification unit that detects whether or not the additional information is included, and identifies the additional information. 3. A communication device comprising a transmission unit and a reception unit for predetermined information to which error control information is added, wherein said transmission unit includes a plurality of pieces of error control information for generating error control information of different systems. Generating means, selecting means for selecting one of the plurality of error control information generating sections according to the additional information to be transmitted, and using the error control information generating section selected by the selecting means, Information transmission means for generating error control information for the predetermined information and transmitting the generated error control information together with the predetermined information, wherein the reception unit includes the error control information included in the received information. A communication apparatus comprising: an additional information identification unit that detects which error control method is used, and identifies the additional information. 4. A communication method for performing communication in an information unit including a header section and a user information section, wherein the user information section includes error control information on user information, and on the transmission side, the error control information includes: A plurality of error control systems are switched according to the additional information to be transmitted, and the receiving side detects the additional information by detecting which of the plurality of error control systems is used. Communication method to be used. 5. A communication method for performing communication in an information unit including a header section and a user information section, wherein the header section includes error control information on header information, and on the transmission side, the error control information is transmitted. A plurality of error control schemes are switched according to the additional information to be obtained, and the receiving side detects the additional information by detecting which of the plurality of error control schemes is used. Communication method. 6. The communication method according to claim 4, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. 7. The communication method according to claim 4, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. A communication method, wherein the information is generated for user information over a plurality of packets. 8. The communication method according to claim 4, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. The communication method, wherein the information is generated for user information in one packet. 9. The communication method according to claim 4, wherein the additional information indicates whether the user information has real-time characteristics. 10. The communication method according to claim 5, wherein the additional information indicates a difference in a data amount of user information included in the information unit. 11. The communication method according to claim 10, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 12. The communication method according to claim 4, wherein the additional information indicates whether the user information has a structure of an IP packet. 13. A communication system in which communication is performed in an information unit including a header section and a user information section, a transmitting side apparatus includes: a header section generation unit configured to generate the header section included in the information unit; A plurality of error control information generating means for generating error control information of different types for the user information included in the user information, and one of the plurality of error control information generating units according to the additional information to be transmitted. Selecting means for selecting, and generating a user information section for adding the error control information generated by the error control information generating section selected by the selecting means to user information included in the information unit to generate the user information section Means, a header section from the header section generating section, and a user information section from the user information section generating section, to the transmitting apparatus as the information unit. A transmitting unit, wherein the receiving-side device includes: an information unit separating unit configured to separate the received information unit into the header unit and the user information unit; and the user information unit separated by the information unit separating unit. A communication system, comprising: additional information identification means for detecting which error control method the included error control information is for, and identifying the additional information. 14. In a communication system for performing communication in an information unit including a header section and a user information section, the transmitting apparatus includes: a user information section generating means for generating a user information section included in the information unit; Header information generating means for generating header information of a header portion included in a unit, and generating a plurality of error control information for generating error control information of different types for the header information generated by the header information generating means Means, selecting means for selecting one of the plurality of error control information generating sections according to the additional information to be transmitted, and error control generated by the error control information generating section selected by the selecting means. A header part generating means for adding information to the header information generated by the header information generating means to constitute the header part; And a sending unit for sending the user information unit from the user information unit generating unit to the receiving device as the information unit, wherein the receiving device sends the received information unit to the header unit. And an information unit separating unit that separates the error control information from the user information unit. The error control information included in the header unit separated by the information unit separating unit detects which error control method is used. And a supplementary information identifying means for identifying the supplementary information. 15. The communication system according to claim 13, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 16. The communication system according to claim 13, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. A communication system characterized in that the information is generated for user information covering a plurality of packets. 17. The communication system according to claim 13, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. A communication system characterized in that the information is generated for user information in one packet. 18. The communication system according to claim 13, wherein said additional information indicates whether the user information has real-time properties. 19. The communication system according to claim 14, wherein said additional information indicates a difference in data amount of user information included in said information unit. 20. The communication system according to claim 19, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 21. The communication system according to claim 13, wherein the additional information indicates whether the user information has a structure of an IP packet. 22. A transmitting apparatus for transmitting communication information in an information unit including a header section and a user information section, wherein: a header section generating means for generating the header section included in the information unit; A plurality of error control information generating means for generating different types of error control information for user information; and a selection for selecting one of the plurality of error control information generating units according to additional information to be transmitted. Means, user information part generating means for generating the user information part by adding error control information generated by the error control information generating part selected by the selecting means to user information included in the information unit, Transmitting means for transmitting, as the information unit, a header part from the header part generating means and a user information part from the user information part generating means. Transmitting apparatus according to claim. 23. A transmitting apparatus for transmitting communication information in an information unit including a header section and a user information section, wherein: a user information section generating means for generating a user information section included in the information unit; Header information generating means for generating header information of a header portion to be generated, a plurality of error control information generating means for generating error control information of different schemes for the header information generated by the header information generating means, Selecting means for selecting one of the plurality of error control information generating units according to the additional information to be transmitted; and transmitting the error control information generated by the error control information generating unit selected by the selecting means to the A header section generating section that configures the header section by adding to the header information generated by the header information generating section; a header section from the header section generating section; Serial transmitting apparatus and a user information unit, characterized in that it and a sending means for sending as the information unit from the user information unit generator. 24. The transmitting apparatus according to claim 22, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. 25. The transmission device according to claim 22, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. The transmission device, wherein the information is generated for user information over a plurality of packets. 26. The transmission apparatus according to claim 22, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. The transmission device, wherein the information is generated for user information in one packet. 27. The transmitting apparatus according to claim 22, wherein the additional information indicates whether the user information has real-time characteristics. 28. The transmitting apparatus according to claim 23, wherein the additional information indicates a difference in a data amount of user information included in the information unit. 29. The transmitting apparatus according to claim 28, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 30. The transmitting apparatus according to claim 22, wherein the additional information indicates whether the user information has an IP packet structure. 31. A receiving apparatus for receiving communication information transmitted in an information unit including a header section and a user information section, comprising: an information unit separation section for separating the received information unit into the header section and the user information section. Means for detecting which one of a plurality of predetermined error control schemes the error control information included in the user information section separated by the information unit separation means is. And a supplementary information identifying means for identifying the supplementary information. 32. A receiving apparatus for receiving communication information transmitted in an information unit including a header section and a user information section, comprising: an information unit separation section for separating the received information unit into the header section and the user information section. Means for detecting which one of a plurality of predetermined error control schemes the error control information included in the header portion separated by the information unit separation means is of. And a supplementary information identifying means for identifying supplementary information. 33. The receiving apparatus according to claim 32, wherein the header section includes destination information, and packet communication is performed in an information unit including the header section and the user information section. . 34. The receiving apparatus according to claim 32, wherein the header section includes destination information, and performs packet communication in an information unit including the header section and the user information section. The information is generated for user information over a plurality of packets, and the additional information identification unit reconstructs the user information over the plurality of packets,
A receiving apparatus for identifying, from the reconstructed user information, which error control method the error control information uses. 35. The receiving apparatus according to claim 32, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. The information is generated for the user information in one packet, and the additional information identification means identifies which error control method is used by the error control information from the user information in the one packet. A receiving device. 36. The receiving apparatus according to claim 32, wherein the additional information indicates whether the user information has real-time characteristics. 37. The receiving apparatus according to claim 33, wherein said additional information indicates a difference in a data amount of user information included in said information unit. 38. The receiving apparatus according to claim 37, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 39. The additional information indicates whether or not the user information has a structure of an IP packet, and the additional information identifying means has identified that the user information has a structure of an IP packet. 37. The receiving apparatus according to claim 32, wherein an IP packet is reconstructed from the user information and the user information is extracted. 40. A communication device comprising a transmitting unit and a receiving unit for performing communication in an information unit including a header unit and a user information unit, wherein the transmitting unit generates the header unit included in the information unit. Generating means; a plurality of error control information generating means for generating different types of error control information for user information included in the information unit; and the plurality of error control information according to additional information to be transmitted. Selecting means for selecting one of the information generating sections; and adding the error control information generated by the error control information generating section selected by the selecting means to the user information included in the information unit, and the user information section User information part generating means for generating a header part from the header part generating means, and a user information part from the user information part generating means as the information unit. A transmitting unit for transmitting, the receiving unit includes: an information unit separating unit configured to separate the received information unit into the header unit and the user information unit; and the user information separated by the information unit separating unit. A communication device comprising: an additional information identifying unit that detects which error control method the error control information included in the unit is, and identifies the additional information. 41. A communication apparatus comprising: a transmitting unit and a receiving unit that perform communication in an information unit including a header unit and a user information unit, wherein the transmitting unit is configured to generate a user information unit included in the information unit Section generation means; header information generation means for generating header information of the header section included in the information unit; and header information generated by the header information generation means. A plurality of error control information generating means, a selecting means for selecting one of the plurality of error control information generating sections according to the additional information to be transmitted, and an error control information selected by the selecting means. A header part generating means for adding the error control information generated by the generating part to the header information generated by the header information generating means to constitute the header part; Sending means for sending a header part from the header part generating means and a user information part from the user information part generating means as the information unit, wherein the receiving part converts the received information unit into the information unit. An information unit separating unit that separates the header unit and the user information unit from each other; and detecting which error control method is used for the error control information included in the header unit separated by the information unit separating unit. And a supplementary information identifying means for identifying the supplementary information. 42. The communication apparatus according to claim 40, wherein said header section includes destination information, and performs packet communication in an information unit comprising said header section and said user information section. 43. The communication apparatus according to claim 40, wherein said header section includes destination information, and performs packet communication in an information unit consisting of said header section and said user information section. The communication device is characterized in that the information is generated for user information over a plurality of packets. 44. The communication device according to claim 40, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. The communication device, wherein the information is generated for user information in one packet. 45. The communication apparatus according to claim 40, wherein said additional information indicates whether the user information has real-time characteristics. 46. The communication apparatus according to claim 41, wherein said additional information indicates a difference in a data amount of user information included in said information unit. 47. The communication apparatus according to claim 46, wherein said header section includes destination information, and performs packet communication in an information unit including said header section and said user information section. 48. The communication apparatus according to claim 40, wherein said additional information indicates whether or not the user information has a structure of an IP packet.