JPH03145242A - Control method for data terminal equipment - Google Patents

Abstract

PURPOSE:To store a transmission control data with a small data size efficiently and to improve the memory utilization efficiency by using a block of a size suitable for a transmission data and a transmission control data respectively. CONSTITUTION:A data transmission control software generating a transmission data stores a transmission data to a buffer set in a common memory area and a transmission control software for each layer processes a transmission data stored in the buffer. On the other hand, a local memory area is allocated to the transmission control software of each layer, and the transmission control software generating the transmission control data stores the transmission control data to the local memory area and the transmission control data stored in the local memory area is transferred to the transmission control software of the next layer. Thus, the processing of the transmission data and the transmission control data differs from each other and the block of the size depending on each is used. Thus, the data transmission control data of a small size is stored efficiently and the memory utilizing efficiency is improved.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a data terminal device equipped with hierarchical transmission control software that independently implements transmission control processing for each of the seven layers of the O3I reference model. Concerning a control method.

[Prior Art] For example, as a model of a protocol (transmission control procedure) for a data terminal device such as a Group 4 facsimile device,
l5O (National VA Standards Organization)'s ○SI (open system interconnection: 0pen System Inter-c)
The OSI reference model of ``Onconnection'' is used as a standard model.

As shown in Figure 8, this ○SI reference model guarantees communication to adjacent open systems such as the physical layer (hereinafter referred to as layer l) for controlling the transmission medium and relay nodes (relay stations). a data link layer (hereinafter referred to as layer 2) to provide communication, a network layer (hereinafter referred to as layer 3) to guarantee communication up to open-ended systems such as data terminals, and a transparent transmission path. a transport layer (hereinafter referred to as layer 4) for controlling conversations, a session layer (hereinafter referred to as layer 5) for conversation control, and a presentation layer (hereinafter referred to as layer 6) for unifying information representation formats.
It consists of seven layers: an application layer (hereinafter referred to as layer 7) for managing the entire system and providing protocols for users.

For example, in two terminals TEa and TEb connected via a transmission medium, a protocol between the same layers is defined (protocol horizontality) so that the communication function works well between the same layers. The interface between each layer is defined so that even if a layer's protocol is changed, it does not affect the protocols of other layers (protocol independence).

In a data terminal device having a hierarchical protocol layer configuration compliant with the O3I reference model, such as a group 4 facsimile device, transmission control software for processing the protocols of each layer is configured independently.

Now, when transmitting image information data with such a group 4 facsimile device, first, the image information data is formed in layer 7, then it is stored in an image storage device, etc., and then layer 6 transmits the image information data. In addition to cutting out each transmission unit, the image information data is converted into a frame by adding header information necessary for layer 6 processing of the destination terminal, and then passed to layer 5.

Layer 5 passes the transmission data to layer 4 with header information necessary for layer 5 processing of the partner terminal added.

Below, layers 4, 3, 2. When each receives and receives transmission data from an upper layer, it adds protocol information necessary for processing by the same layer of the other terminal, and in that state passes the transmission data to a lower layer.

In this way, the transmission data output from layer 1 to the transmission medium MD is sequentially layered into layers 6, 5, 4, and 1 frame worth of communication data (in this case, image information data), as shown in FIG. , 3, 2 header information is added.

On the other hand, a terminal device that receives such transmission data processes the header information corresponding to layers 2, 3, 4, 5, and 6 in order, and if it is necessary to pass it to a higher layer, it sends the same information to the upper layer. Pass the transmission data with layer header information removed.

Separately, before transmitting one piece of communication data, protocol processing is performed between the respective layers of the two terminals to negotiate and adjust the functions to be used.

At the transmitting terminal, the transmission control data used for this protocol processing is sequentially passed from the layer that generated the transmission control data to lower layers.

The data is sent to the other party's terminal via the transmission medium, and at the receiving terminal, the corresponding header information is removed in the lower layer, and the data is passed to the layer that receives and receives the transmission control data.

Therefore, the transmission control data is sent to the transmission medium with header information below the layer that generated it added.

Now, conventionally, the transmission data of the frame carrying the image information data as described above and the transmission data of the frame carrying the transmission control data generated in accordance with the protocol processing of each layer are transmitted through the same route to the other party. Since the data is sent to the terminal, conventionally, these data were not differentiated and were processed in the same manner.

In other words, the maximum size of frame transmission data that carries image information data is 2053 octets (bytes), and in order to perform window processing, it is necessary to hold the maximum frame of transmission data, so the data size increases. A plurality of 14,371-byte blocks were secured in memory, and transmission data was processed in units of blocks.

[Problems to be solved by the invention] However, in such data terminal devices, conventional
This caused the following inconveniences.

For example, when using a packet-switched network as a transmission medium, a 2053-octet block is used to process the RR frame, which is layer 2 transmission control data, even though the size is only 4 octets. As a result, memory usage efficiency was poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data terminal device control method that can eliminate such inconveniences and improve memory usage efficiency.

[Means for Solving the Problems] According to the present invention, transmission control software that has generated transmission data stores the transmission data in a buffer set in a common memory area, and transmission control software in each layer stores the transmission data in the buffer. While processing the transmission data that has been sent, a local memory area is allocated to the transmission control software in each layer, and the transmission control software that generated the transmission control data stores the transmission control data in its local memory area and performs the following processing. The transmission control data stored in the local memory area is delivered to the hierarchical transmission control software.

[Effects] Therefore, transmission data and transmission control data are handled differently, and blocks of the appropriate size can be used for each. Therefore, transmission control data with a smaller data size can be stored efficiently, improving memory usage efficiency. do.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a facsimile machine according to an embodiment of the present invention. This facsimile H'll has both group 3 facsimile machine functionality and group 4 facsimile machine functionality.

In the figure, a control unit 1 executes operation control processing of the facsimile machine, group 3 facsimile transmission procedure processing, group 4 facsimile transmission procedure processing of the upper layer, and call procedure processing, and system memory 2 , stores a processing program executed by the control unit l and various data necessary for executing the processing program, and constitutes a work area of the control unit l. The parameter memory 3 is for storing various types of information specific to this facsimile machine, and is stored from a rewritable nonvolatile semiconductor storage device such as a battery-backed SRAM (static random access memory). Become.

The character generator 4 is for generating image data of graphic characters to be added to the image, and is for generating image data of graphic characters to be added to the image.
is for obtaining current time information.

The scanner 6 is for reading the original image at the resolution set in the group 4 facsimile device,
The plotter 7 records and outputs images at the resolution set in the group 4 facsimile device.

The operation display section 8 is used to operate the facsimile machine, and includes various operation keys and various display devices such as a liquid crystal display for displaying guidance information to the operator.

The encoding/decoding unit 9 encodes and compresses the image signal using a predetermined encoding method, and also decodes the encoded and compressed image information into the original image signal, and performs pixel density conversion. The unit 10 is for converting the pixel densities of the images of the scanner 4 and the plotter 5 and the image that can be transmitted by the destination terminal device, when the pixel densities of the images are different.

The image storage device 11 stores transmission image signals and transmission image information.

This is for storing various information such as received image information and received image signals.

The l5DN interface circuit 12 is for physically connecting with the l5DN, and is for layer 1 signal control unit 13.
is equipped with an I5DN layer 1 signal processing function and an integration/separation function of a D channel (signal channel) signal and two B channel (information channel) signals.

The D channel transmission control unit 14 uses the D channel to
The C0DEC15 is for performing transmission control processing such as call control processing with the DN, and the C0DEC15 is for performing signal conversion processing of analog signals/digital data for transmitting analog signals using the B channel of the 15DN. It is.

The B channel transmission control unit 16 controls the B channel (
This is for performing transmission control processing of layers 2, 3, and 4.5 of group 4 facsimile transmission control processing using the information channel).

The group 3 facsimile modem 17 is for realizing the group 3 facsimile modem function, and has a low speed modem function (V,
21 modem) and a high-speed modem function (V, 29 modem, V, 27ter modem) mainly for exchanging image information.

The switch 18 is used to switch and connect the CODEC 5 to either the group 3 facsimile modem 17, the handset 19 for making calls, or the speaker 20 for outputting a ring tone or the like.

Control section 1, system memory 2, parameter memory 3, character generator 4, clock circuit 5, scanner 6, plotter 7, operation display section 8, encoding/decoding section 9, pixel density conversion section 101 image storage device 11. D channel transmission control section 14, C0DEC 15, B channel transmission control section 16,
Group 3 fax machine modem 17° and switch 1
8' is connected to an internal bus 21, and exchange of various information between these elements is mainly performed via this internal bus 21. Also, handset 19
The hook signal FS that detects the hook status of the internal bus 2
1 to the CPUI.

Here, a description will be given of a call setup/call release procedure that an ISDN terminal such as a facsimile machine performs with an I5D-N during data transmission.

That is, as shown in Fig. 2, the originating terminal first sets the terminal functions to be used, and sends a call setup message 5ETUP specifying the destination terminal to the ■SDN to set up a call with the destination terminal. The I5DN then sends a call setup message 5ETUP in which the identification information (ISDN address) of the originating terminal and the terminal functions are set to the specified destination terminal, and makes a call. The I5DN also sends a call setup acceptance message CALL-PROC to the calling terminal to notify the call setup status.

When the destination terminal detects an incoming call, it sends a paging message ALE to the l5DN if the terminal is ready to receive the call.
RT is sent out continuously at predetermined intervals, and the SDN sends out a paging message ALERT to the calling terminal to notify that it has started calling the called terminal.

When the destination terminal responds to the incoming call, it sends a response message C0NN.
5DN, and the 15DN sends a response message C0NN to the originating terminal to notify that the terminating terminal has accepted the call.

In addition, l5DN sends a response confirmation message C0N to the first destination terminal.
A NACK is sent to confirm the response of the destination terminal, and at that point, an information channel (B channel) for data transmission is established between the originating terminal and the destination terminal.

According to this, data transmission using the information channel between the originating terminal and the destination terminal is executed according to the transmission control procedure set in the transmission function of each terminal.

When the data transmission is finished, the originating terminal and the terminal send a disconnection message DISC to the 15DN to request release of the information channel, and the SDN sends a disconnection message DISC to the destination terminal to notify that the information channel has been restored.

As a result, when the first destination terminal responds to the l5DN with a release message REL notifying completion of channel disconnection, the release message REL is sent from the l5DN to the originating terminal. When the channel release is completed, the originating terminal sends a release completion message RE.
L-COMP is sent to l5DN to notify it, and as a result, l5DN sends a release completion message REL-C.
By sending the OMP to the destination terminal, the information channel is released, and the information channel set between the originating terminal and the destination terminal is completely released.

In this way, an information channel is set up between the originating terminal and the destination terminal, data transmission is performed, and when the data transmission is completed, the information channel is released.

FIG. 3 shows an example of a transmission control procedure performed by a group 4 facsimile device with a partner terminal during data transmission. In this example, 15O8208 is used as the layer 3 protocol in circuit switching mode, and the number of documents to be transmitted is two.

First, the originating terminal sends the command SABME to activate layer 2 of the destination terminal, and after confirming the establishment of layer 2 (procedure class adjustment), the destination terminal sends the command SABME to activate layer 2 of the destination terminal. , signal SQ is sent, and if the destination terminal accepts it, it responds with signal SF.

In this way, when layer 3 is established, the one-originating terminal sends a block TCR to request a layer 4 connection, and if the M terminal accepts it, it sends a block TCR.
Response A (block size adjustment).

When Layer 4 is established, the originating terminal sends a command C3S to instruct the start of Layer 5, and if the destination terminal accepts it, it responds with a response R35P (window size adjustment''!). 1).

When layer 5 is established, it sends the command CDCL to notify the terminal capabilities used in layer 6 (document layer (= presentation layer)).
The destination terminal responds with a response RDCLP if the function can be protected.

When the setting of the transmission function is completed in this way, the originating terminal sends the command CDS to notify the start of transmission of document h, cuts out the transmission data (image information data) in l block units, and frames it. Send by CDUI.

When the transmission of the image information for the first page is completed, the originating terminal sends a command CDPB to notify that the page has ended (that is, there is a subsequent page), and the destination terminal normally receives the image information for the first page. In this case, a response RDPBP is sent as a response.

In this way, when the transmission of the image information of the first page is completed, the originating terminal transmits the image information of the second page using the frame cou r in the same way as the image information of the first page, and transmits the image information of the second page. When the information transmission is finished, a command CD[E is sent to indicate the end of the document. If the destination terminal has normally received the image information of the second page, it responds with a response RDEP.

When all the image information has been transmitted in this way, the originating terminal sends the command C5E to notify the end of layer 5, and the destination terminal responds with a response R if it accepts it.
Reply with 3EP.

When layer 5 is successfully terminated, the originating terminal sends a command CQ to terminate layer 3, and the destination terminal responds with a response CF when accepting it.

When layer 3 is successfully terminated, the originating terminal sends a command DISC to terminate layer 2, and the destination terminal responds with a response UA if it accepts it.

In this way, image information is transmitted on the B channel.

In this embodiment, the transmission control process executed by the control unit 1 and the 8-channel transmission control unit 16 during image information transmission is configured as shown in FIG.

In other words, the tasks in charge of processing each layer are configured independently, and the operating system manages resources such as a common area of memory, and when each task requests them, the operating system allocates the resources to the requested task. I am trying to allocate it.

However, transmission control data is exchanged between adjacent tasks.

In addition, as shown in FIG. 5, a part of the work area formed in the system memory 2 is allocated to each task so that each task can use it independently, mainly for storing transmission control data, etc. area LAR,
A common area CAR is formed in which communication data commonly accessed by each task is stored, and the common area CAR is treated as a resource by the operating system.

As shown in FIG. 6(a), the common area CAR includes an area HTMC for storing a common area management table for managing the common area CAR, and a plurality of areas corresponding to the large capacity of communication data. Area B D A consisting of blocks of
Consisting of The operating system allocates blocks of area BDA to tasks.

As shown in FIG. 3(b), the common area management table includes table number information TID for identifying the common area management table, and task identification information for identifying the task to which the common area management table is assigned. TSK,
Start address information TAD that stores the start address of the block corresponding to the common area management table, byte number information TON that stores the size of valid data stored in that block, and the block that can be released by the task. It consists of a releasable flag FRL that indicates whether or not this is the case.

When transmitting image information data with the above configuration.

The layer 7 task operates the scanner 6 to read the image signal of the transmission document, encodes and compresses the image signal in the encoder/decoder 9, and stores the resulting image information in the image storage device 11.

In this way, while the transmission image information is stored in the image storage device 11, the layer 6 task cuts out the image information data stored in the image storage device 11 in units of blocks and transfers it to the layer 6 task area. (area LAR) is used to form the frame cour and request block allocation from the operating system.

This causes the operating system to
Unused (
Select one task whose task identification information is blank, and enter the table number information TID of that common area management table.
Notify the layer 6 task of the contents.

Layer 6 task uses table number information TID that matches the table number notified from the operating system.
Looking for a common area management table with.

The identification information set for the own task is recorded in the task identification information TS, and the data of the frame CDUI is sequentially stored from the address stored in the start address information TA port of the common area management table. The number of bytes of the frame CDUI is set in the byte number information TBN of the common area management table. Also, at this time, if the releasable flag FRL is set and the frame CDUI is saved in any block of area B [lA, the layer 6 task will be able to send data to the layer 5 task. At the same time, the table number information T of the common area management table corresponding to the block storing the frame CDUI data is notified.
Notify ID.

As a result, the layer 5 task obtains the start address of the block storing the data of the frame CDUI from the start address information TAD of the common area management table of the table number information TID notified by the layer 6 task,
From that address, data of the number of bytes stored in the byte number information TBN is read, header information is added to the read data, and the data is stored again in the same block. Furthermore, the layer 5 task stores information that identifies the task itself in the task identification information 1''SK of the common area management table.

The number of bytes of data stored in the block is stored in the byte number information TBN.

When the header information is added in this way, the layer 5 task notifies the layer 4 task that there is data to be sent, and also notifies the table number information TID notified from the layer 6 task.

After this, table number information TID of the common area management table is sequentially notified to lower tasks, and header information is sequentially added to the frame COUR to form transmission data (see FIG. 7).

This operation is repeated for each frame, and the image information data stored in the image storage device 11 is transmitted to the other party's terminal.

Further, the operation when transmitting the transmission control data will be explained next.

First, each task forms a management table similar to the common area management table that the operating system forms in the common area CAR in the area LAR assigned to the task.

Similar to area BDA, a plurality of blocks are formed with a capacity corresponding to the size of transmission control data. However, in this case, instead of table number information, information on the start address of the management table (hereinafter referred to as table address) is set in the management table.

For example, when a layer 6 task forms a command CDCL, it stores the command CDCL in an empty block in the area LAR assigned to the self-task, and sets task identification information and byte count information in the management table corresponding to the block. and also with the releasable flag reset.

The layer 5 task is notified of the existence of transmission control data, and is also notified of the table address information of the management table.

As a result, the layer 5 task reads the management table by referring to the table address information notified from the layer 6 task, and transfers the transmission control data of the number of bytes indicated by the byte number information to the layer 6 from the address indicated by the start address information. The data is extracted from the area LAR assigned to the task, and header information is added to the extracted transmission control data. Next, the data is stored from the same start address, the byte count information is changed, the task identification information is changed, the layer 4 task is notified that there is transmission control data, and the table address of the management table is changed. Notify information.

From this point on, lower layer tasks are sequentially notified of the presence of transmission control data and the table address information of layer 6 tasks, and each task adds corresponding header information to generate its transmission control data. The data is stored in the block of the area LAR assigned to the assigned task and sent out to the transmission medium.

In this way, transmission control data is saved in a block of the storage area managed by the task that generated the transmission control data, and is accessed from a task in a lower layer. The size of the block formed in each task area can be significantly reduced, resulting in improved memory usage efficiency.

In the above-described embodiment, the present invention is applied to a group 4 facsimile device that uses an 15DN as a transmission line, but the present invention can be similarly applied to other data terminal devices.

Furthermore, the storage management method described above is just an example, and other methods may also be used.

In addition, in the embodiment described above, the layer 3 protocol is used as the B channel protocol in circuit switching mode.
8208, but the present invention can be similarly applied to terminal devices that use other protocols.

[Effects of the Invention] As described above, according to the present invention, the transmission control software that has generated transmission data stores the transmission data in a buffer set in a common memory area, and the transmission control software of each layer.

While processing the transmission data stored in the buffer, a local memory area is allocated to the transmission IIJ control software of each layer, and the transmission control software that generated the transmission control data stores the transmission control data in the local memory area. At the same time, the transmission control data stored in the local memory area is passed to the next layer of transmission control software, so the handling of transmission data and transmission control data is different, and each block size is divided according to the data. Therefore, it is possible to efficiently store transmission control data with a smaller data size, thereby achieving the effect of improving memory usage efficiency.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a Group 4 facsimile device according to an embodiment of the present invention, Fig. 2 is a time chart showing an example of the transmission procedure when SDN is used as the transmission path, and Fig. 3 is A time chart showing an example of the B channel transmission procedure, Fig. 4 is a schematic diagram showing an example of the configuration of control software, Fig. 5 is a schematic diagram showing an example of the configuration of the work area of the system memory, and Fig. 6 (a) is a common diagram. A schematic diagram showing an example of the structure of the area, (b) is a schematic diagram showing an example of the common area management table, FIG. 7 is a schematic diagram showing an example of the communication data formation method, and FIG. 8 is the ○SI reference model. FIG. 9 is a schematic diagram showing an example of the format of communication data. 1... Control unit, 2... System memory, 16...
B channel transmission control section. Figure 1 Figure 6 (a) AR (b) Figure

Claims (1)

[Claims] In a method for controlling a data terminal device equipped with hierarchical transmission control software that independently implements transmission control processing for each of the seven layers of the OSI reference model, the transmission control software that has generated transmission data is stored in a common memory area. The transmission data is stored in a buffer set to Data characterized in that the transmission control software that has generated the control data stores the transmission control data in its local memory area and also passes the transmission control data stored in the local memory area to the next layer of transmission control software. A method of controlling a terminal device.