JP3279900B2 - Data communication device and data communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication device and a data
More particularly, the present invention relates to a data communication device and a data communication method capable of suppressing a decrease in throughput when an error occurs in a wireless section.

[0002]

2. Description of the Related Art Data communication apparatuses for communicating between remote places are widely used in various fields. In these data communication devices, the data to be transmitted is temporarily stored in case the data transmission speed differs between the transmission side and the transmission line, or when an error occurs in the transmission line and the data must be retransmitted. In many cases, a transmission buffer device is provided. In the transmission buffer device, the amount of data that can be stored is determined. Therefore, the data communication device controls the flow so that the amount of transmission data to be stored does not exceed the data amount in order to reliably transmit the transmission data.

[0003] As shown in FIG.
1, a data terminal device (hereinafter referred to as DTE)
The data generated by 52 is temporarily stored in a transmission buffer device 53. After that, the modulation device 54 modulates the data stored in the transmission buffer device 53 into a signal suitable for communication, and transmits the signal to a receiving device (not shown) via the communication medium 55. On the other hand, a signal transmitted from the receiving device via the communication medium 55 is demodulated by the demodulation device 56 and then demodulated.
Sent to TE52.

If the data transfer speed between the modulator 54 and the receiving device is lower than the data transfer speed between the DTE 52 and the modulator 54, the transmission buffer device 5
3, the amount of data stored therein increases. Flow control device 5
7 monitors the amount of data in the transmission buffer device 53 and performs flow control on the DTE 52 when the data amount exceeds a predetermined value. As a result, the DTE 52 stops generating data.

Since the data communication device 51 controls the data generation speed in the DTE 52 in accordance with the amount of data in the transmission buffer device 53, the data transfer between the modulation device 54 and the reception device is smaller than that between the DTE 52 and the modulation device 54. Even if the speed is slow, data can be transferred reliably.

On the other hand, in order to use the transmission path efficiently,
A data communication device that adopts a digital transmission method instead of a method of transmitting transmission data in an analog manner and divides transmission data into a plurality of slots and transmits the data is widely used. This includes, for example, a wireless modem device using a wireless communication device, such as a personal handyphone system (hereinafter, referred to as a PHS).

[0007] As shown in FIG.
In 1, the slot generation device 64 generates a slot handled by the PHS 62 from the transmission data received from the DTE 63, and stores the slot in the transmission buffer device 65. On the other hand, P
The HS 62 extracts a transmission slot from the transmission buffer device 65. Then, at predetermined time intervals, the data is transmitted to a receiving device (not shown) via a wireless section. Since the time interval for transmitting the slot is determined to be, for example, every 5 ms, each slot does not necessarily contain the data in the full amount of information of the slot.

For example, if the data transfer rate between the DTE 63 and the slot generator 64 is 9600 bps, the PHS 6
Assuming a data transfer rate of 32 Kbps from No. 2 to the wireless section, each slot normally contains about 30% of transmission data.

On the other hand, due to the deterioration of the condition of the radio section,
When the reception of the slot fails, the receiving device specifies the slot that has not reached to the data communication device 61. Based on this, the error control device 66 performs error control,
The PHS 62 retransmits the slot. During retransmission, a new slot cannot be transmitted.
The number of slots stored by 5 increases. When the number of slots increases and exceeds a predetermined value, the flow control device 67
The flow control is performed on the TE 63. According to this, DT
E63 stops generation of transmission data.

[0010]

However, in the data communication device 61 having the above configuration, the retransmission due to the radio section error directly leads to the flow control for the DTE 63, so that even if the data transfer speed of the PHS 62 has a margin, the throughput is low. There is a possibility that it will undesirably decrease.

For example, if the data transfer rate of the DTE 63 is 9
Assuming that the data transfer rate from the PHS 62 to the receiving device is 32 Kbps at 600 bps, the PHS 62 transmits correct transmission data at 16 Kb when retransmitting 50% of the slots.
It can be transmitted at about ps. Since this speed is higher than the data transfer speed of the DTE 63, a throughput of 9600 bps should be obtained as in the case where no slot is retransmitted. However, in the data communication device 61,
Since the flow control device 67 performs flow control on the DTE 63, the DTE 63 stops for one slot every two slots. Therefore, the data transfer rate of the DTE 63 drops to about 4800 bps. As a result, the actual throughput is only about 4800 bps.

When a wireless transmission path is used, the state of a wireless section deteriorates due to movement of a data communication device, and errors in the wireless section are likely to increase. Therefore, flow control is performed more frequently than in the case of wired communication. As a result, when the throughput is undesirably reduced during the flow control, the adverse effect is extremely large.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress a decrease in throughput when an error in a transmission line increases in a data communication device.

[0014]

In order to solve the above-mentioned problems, a data communication apparatus according to the present invention divides transmission data and generates a slot as a unit at the time of communication; In the data communication device having a temporary storage unit for temporarily storing the data, and a transmission unit for reading and transmitting the slot from the temporary storage unit, when the flow control in which the number of slots stored in the temporary storage unit is increased, the slot generation unit Transmission time occupying the slot by extending the time interval for generating the slot compared to the normal time
It is characterized in that it comprises a control means for Ru increase the rate of data.

In the configuration described above, the slot generating means normally generates slots at predetermined time intervals, for example, 5 ms, from the transmission data generated by the data generating means (data terminal device) . After being stored in the temporary storage unit, the slot is transmitted by a transmission unit such as a PHS. In this case, the transmission data is not always included until the information amount of the slot is full.

For example, when retransmission of data is repeated due to deterioration of the state of the radio section, the speed at which the transmitting means correctly transmits a slot is lower than the slot generation speed by the slot generating means. Therefore,
The number of slots stored in the temporary storage increases.

For example, upon detecting that the number of slots exceeds a predetermined value, the control means performs flow control on the slot generation means, and sets the time interval at which the slot generation means generates slots as compared with the normal time. Extend it. As a result, the slot generation speed decreases, and an increase in the number of slots can be suppressed. In this state, the data generation unit generates transmission data as in the normal case, and the proportion of the transmission data in each slot increases.

Therefore, it is possible to suppress the speed of accumulating the slots in the temporary storage means without lowering the speed at which the data generation means generates transmission data. Therefore, at the time of flow control, a decrease in throughput in the data communication device can be suppressed.

In order to solve the above-mentioned problems, a data communication apparatus according to the present invention divides transmission data and sets a unit for communication.
Slot generating means for generating a slot to be
Temporary storage means for temporarily storing the slot
Transmission means for reading and transmitting a slot from the
In the data communication device, the temporary storage unit stores
During flow control with an increased number of slots,
The time interval at which the generating means generates slots is compared with the normal time
Control means for delaying the slot generation by the slot generation means until the transmission data is full of the information amount of the slot.

According to the above configuration, the slot generating means includes:
At the time of flow control, a slot that is full of transmission data is generated. As a result, the transfer speed of the transmission data by the transmission means is maximized. Therefore, a decrease in throughput can be further suppressed.

In order to solve the above-mentioned problems, the data communication device according to the present invention further comprises a data communication device.
The transmission data generated by the data terminal
Be one that transmitted every, depending on the number of slots the temporary storage means for storing, it is characterized in that the data terminal equipment is equipped with a data generation control means for controlling the speed for generating transmission data .

In the flow control, if the number of slots in the temporary storage unit further increases even if the control unit decreases the slot generation speed of the slot generation unit, the data generation control unit stops the data generation unit, for example. For example, the speed at which the data generating means generates transmission data is reduced. This limits the slot generation speed by the slot generation means.

As a result, even in a data communication device that performs flow control on the slot generation means, it is possible to reliably prevent the temporary storage means from overflowing. Therefore, transmission data loss due to overflow can be prevented.

Further , the data communication device according to the present invention
Data to generate transmission data to solve the problem
Generating means for dividing the transmission data to be a unit during communication.
Slot generating means for generating a slot to be
Temporary storage means for temporarily storing lots, and temporary storage means
Transmission means for reading and transmitting a slot.
In the data communication device, the slot stored in the temporary storage means is stored.
The above slot generation is performed during flow control when the number of
The time interval during which the means generates slots is
The transmission data is full of the information amount of the slot.
Until the slot generation means
It is characterized by having a control means for delaying.

[0025] The data communication apparatus according to the present invention has the above-mentioned problems.
In order to solve the problem, the temporary storage means further stores
The data generation means sends the transmission data according to the number of slots
Data generation control means for controlling the speed of generating
It is characterized by having.

Also, the data communication method according to the present invention
In order to solve the problem, the transmission data is divided
Slot generation processing to generate a slot as a unit of time
And temporarily store the slot in the transmission buffer device.
Storage processing and reading the slot from the transmission buffer device
A data communication method including a sending process of sending out and sending.
Therefore, the number of slots stored in the transmission buffer device increases.
In addition, when the first flow control start value is exceeded,
The time interval for generating slots in the generation process is
To increase the percentage of transmitted data in the slot
It is characterized by including a control process for causing

[0027] The data communication method according to the present invention provides the above-mentioned object.
In addition, in order to solve
Slot until the slot is full of information.
The feature is that the slot generation in the
are doing.

[0028] The data communication method according to the present invention provides the above-mentioned object.
In order to solve
Reduce the speed of slot generation in the slot generation process.
However, the number of slots stored in the transmission buffer device is
When it further increases and exceeds the second flow control start value,
Transmission data at the data terminal device that generates the transmission data
Including data generation control processing to reduce the generation speed
Features.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
This will be described below with reference to FIG. That is, as shown in FIG. 1, a data communication device 1 according to the present embodiment uses a personal handyphone system (hereinafter, abbreviated as PHS) 2 as a transmission unit, via a wireless transmission path. It can communicate with a connected receiving device (not shown).

The data communication device 1 includes a data terminal device (data generation means; hereinafter, D
This transmission data is divided and P
Error control is performed on the basis of instructions from the slot generation device (slot generation means) 4 for forming slots handled by the HS 2, the transmission buffer device (temporary storage means) 5 for temporarily storing the generated slots, and the reception device. , An error control device 6 for retransmitting the unreachable slot. Further, the data communication device 1 according to the present embodiment includes:
A flow control device (control means) 7 for monitoring the number N of slots accumulated in the transmission buffer device 5 and performing flow control for the DTE 3 and the slot generation device 4 is provided. Thereby, prior to the flow control on the DTE 3, the flow control is performed on the slot generation device 4.

The PHS2 is, for example, PHS or PHS
It is a compatible home digital cordless telephone or the like, and can transmit the slots stored in the transmission buffer device 5 to the receiving device via a wireless section at predetermined time intervals. PHS
In PHS, this time interval is set to 5 ms, and PHS
2 can transmit 200 slots per second.

In addition, the slot generation device 4 has a DTE
TCH (audio part) in slot
And a slot handled by the PHS2 can be generated.
Since the PHS 2 transmits a slot every 5 ms, the slot generating device 4 separates transmission data from the DTE 3 every 5 ms and generates one slot.

Each of the slots has a maximum of 20 bytes of information (including information on error control, slot management, etc.). However, since the time interval for generating the slot is determined, the transmission data does not always fill the information amount of the slot.

Further, the slot generation device 4 according to the present embodiment can delay the slot generation timing based on the instruction of the flow control device 7. in this case,
The slot generation device 4 generates a slot after receiving from the DTE 3 transmission data having the full information amount of the slot. As a result, the time interval when generating a slot is
It increases from 5 ms.

The error control device 6 receives information from a receiving device (not shown) as to whether the transmitted slot has arrived correctly. When an error occurs in the wireless section, the receiving device specifies a slot that has not reached to the data communication device 1. Based on this, the error control device 6
Controls the transmission buffer device 5 to retransmit slots that have not reached.

Further, the flow control device 7 according to the present embodiment is configured so that the transmission buffer device 5 stores the number of slots N
And the flow control can be performed on the DTE 3 and the slot generation device 4. Specifically, the number of slots N is the first
When the flow control start value A is exceeded, the flow control device 7
Can output a signal for delaying slot generation to the slot generation device 4. When the number of slots N exceeds the second flow control start value B, the flow control device 7
E3 can be stopped.

The values A and B are set so that the relationship 1 <A <B <n holds when the number of slots that can be stored in the transmission buffer device 5 is n. Note that these values are set in advance so as to be optimal according to the circuit configuration, the communication method, and the like.

Thus, the data communication apparatus 1 is in the normal communication state in which no flow control is performed according to the number of slots N, and the first flow control in which the flow control is performed on the slot generation apparatus 4. By shifting between the state and the second flow control state in which flow control is performed on the DTE 3 and the slot generation device 4, flow control can be performed in two stages.

In addition, the data communication device 1 includes a slot disassembly device 8. The slot decomposing device 8 can decompose a slot received by the PHS 2 from a receiving device (not shown) and extract data. The extracted data is sent to DTE3.

Next, in the above configuration, the operation of the flow control device 7 at the time of transmission will be described below for each step based on the flowchart shown in FIG.

In the first step 1 (hereinafter abbreviated as S1), the flow control device 7 monitors the number of transmission slots stored in the transmission buffer device 5 and determines that the number N of slots is equal to the first flow number. It waits until the control start value A is exceeded.

While N ≦ A, the flow control device 7
3 and the slot generation device 4 are not subjected to flow control. The state where flow control is not working, that is,
In the normal communication state, the DTE 3 keeps generating transmission data. In addition, the slot generation device 4 outputs 1 every 5 ms.
A slot is generated and stored in the transmission buffer device 5.
On the other hand, the PHS2 transmits slots to the wireless section at intervals of 5 ms.

When the radio section is in a normal state, the speed at which the slot generation device 4 generates slots and the speed at which the PHS 2 transmits slots are balanced, and the transmission buffer device 5 stores a small amount of slots. In the state of being. As a result, the slot number N is smaller than the predetermined value A, and the flow control device 7 repeats S1.

During this period, the slot generation device 4
Regardless of the amount of data received from E3, a slot is generated every 5 ms. Therefore, the slot does not always contain the transmission data to fill the information amount of the slot. As a result, in each slot,
In many cases, there is an empty area that does not contain transmission data.

On the other hand, when the state of the radio section deteriorates, the number of errors increases, and slots occur in which a receiving device (not shown) cannot normally receive. In this case, the receiving device transmits to the data communication device 1 which slot has not reached. The error control device 6 performs error control on the transmission buffer device 5 based on the feedback from the receiving device, and causes the unreachable slot to be transmitted again. While the slot is being retransmitted, the slot newly generated by the slot generation device 4 cannot be transmitted. Therefore, the number of slots N of the transmission buffer device 5 gradually increases.

When communication errors occur frequently and slots larger than the first flow control start value A are accumulated in the transmission buffer device 5 (in the case of YES in S1), the flow control device 7
Starts flow control for the slot generation device 4,
An instruction is given to delay the slot generation (S2). Subsequently, in S3 and S4, the flow control device 7
The number of slots N of the transmission buffer device 5 is monitored, and S3 and S4 are repeated while the number of slots N is within the range from the first flow control start value A to the second flow control start value B.

While S3 and S4 are repeated, the flow control device 7 performs flow control on the slot generation device 4. In this first flow control state, the slot generation device 4 delays the slot generation and
The slot is generated after the transmission data from the CPU has reached the full amount of information held by the slot. On the other hand, since the time interval for transmitting the slot to the wireless section is predetermined, the PHS2 transmits the slot at an interval of 5 ms as usual. Also, since flow control is not performed on the DTE 3, the DTE 3 sends out transmission data to the slot generation device 4 at the same speed as in the normal communication state.

In the first flow control state performed before the flow control to the DTE 3, a slot is generated every time transmission data is filled in the slot. Therefore, the slot generation device 4 can receive the transmission data without missing the transmission data from the DTE 3. on the other hand,
Since the slot generation is delayed, the slot generation device 4
, The slot generation speed is suppressed as compared with the normal communication state.

Therefore, compared to the normal communication state, the speed at which slots are accumulated in the transmission buffer device 5 can be reduced without lowering the throughput. Further, each slot contains transmission data from the DTE 3 up to the full information amount of the slot. Thereby, the transfer rate of the transmission data in the PHS2 is kept at the maximum within the range of the transmission rate of the slot.

As a result, when the data transfer speed from the DTE 3 is relatively low and the speed of the slot transmission by the PHS 2 is faster, the reading speed of the slot in the transmission buffer device 5 is higher than the speed of newly accumulating the slot. That is, the number of slots N decreases.

When the number of slots N decreases and becomes smaller than the value A (YES in S4), the flow control device 7
Releases the flow control for the slot generation device 4 (S5), and then returns to S1 to perform the processing. Further, the slot generation device 4 generates a slot every 5 ms based on the instruction. As a result, the data communication device 1 shifts to the normal communication state.

In the processing of S1 to S5, since the flow control device 7 does not perform the flow control on the DTE 3, the DTE 3 continues to transmit the transmission data.
Therefore, when the flow of the transmission buffer device 5 can be solved by the flow control for the slot generation device 4, the throughput of the data communication device 1 does not decrease.

On the other hand, in the first flow control state, D
If the data transfer rate from the TE3 is relatively high or if there are many errors in the wireless section, the slot transmission rate of the PHS2 will not increase the data transfer rate from the DTE3 even if the flow control device 7 controls the flow of the slot generation device 4. It may be slower than the speed. In this case, in the transmission buffer device 5, the speed at which the PHS 2 reads out slots is lower than the speed at which the slot generation device 4 accumulates slots, and the number of slots N increases.

When the number of slots N becomes larger than the B value (YES in S3), the flow control device 7
The flow control of No. 3 is performed, and a transition is made to the second flow control state (S6). Specifically, in S6, the flow control device 7
Sends a data transmission prohibition request to DTE3,
No. 3 stops data generation. Further, in S7, the flow control device 7 monitors the number of slots N of the transmission buffer device 5, and waits until the number of slots N becomes smaller than the second flow control start value B.

In the second flow control state, DTE3 is
Since no data has been generated, the new transmission slot
It is not stored in the transmission buffer device 5. Therefore, the number of slots N decreases as PHS2 transmits slots.

When the number of slots N becomes smaller than the value B (S
7, when YES), the flow control device 7
Is released (S8). Based on this, D
TE3 starts generating data. After that, the flow control device 7 repeats the processing after S3, and the data communication device 1 shifts to the first flow control state.

As described above, the data communication device 1 according to the present embodiment includes the slot generation device 4 for delaying slot generation and extending the time interval for slot generation and the transmission buffer device 5 during flow control. A flow control device 7 that performs flow control on the slot generation device 4 prior to flow control on the DTE 3 according to the number of slots N
It has.

In the above configuration, when the speed at which the PHS 2 reads out slots from the transmission buffer device 5 decreases due to deterioration of the radio section and the number N of slots in the transmission buffer device 5 increases, the flow control device 7
Before performing flow control on slot 3, the slot generation device 4
Perform flow control on. Based on this, the slot generation device 4 extends the time interval for generating a slot.

Therefore, the slot generation speed of the slot generation device 4 can be reduced without lowering the data transfer speed from the DTE 3. As a result, the speed of slots accumulated in the transmission buffer device 5 is reduced, and overflow of the transmission buffer device 5 can be prevented. As a result, in the data communication device 1, a decrease in throughput during flow control can be suppressed.

When the flow control is performed, the slot generation device 4 according to the present embodiment waits for transmission data to fill the information amount of the slot and generates the slot. However, the present invention is not limited to this. Not something. For example, usually
The time interval of 5 ms slot generation may be increased to a fixed value, such as 10 ms. By extending the time interval of slot generation within a range where transmission data from DTE 3 is not lost, the same effect as in the present embodiment can be obtained.

However, the slot generation device 4 according to the present embodiment waits for generation of a slot until transmission data is filled to the full amount of information of the slot. As a result, the ratio of transmission data in each slot can be always maximized. Therefore, the state of the radio section deteriorates, and the PHS
Until the transmission speed of the normal transmission data by 2 decreases, the same throughput as the normal time can be maintained. As a result, a decrease in throughput can be further suppressed as compared with a case where the time interval of slot generation is extended regardless of the amount of transmission data.

Further, since the slot generation device 4 according to the present embodiment monitors the amount of transmission data, even if the data transfer speed from the DTE 3 changes, transmission data will not be missed. Therefore, the data communication device 1 can reliably transmit transmission data.

Further, the flow control device 7 according to the present embodiment stops the DTE 3 when the slot generation means of the transmission buffer device 5 exceeds the second flow control start value B. As a result, the slot generation device 4 does not accumulate new slots in the transmission buffer device 5. As a result, overflow of the transmission buffer device 5 can be reliably prevented, and loss of transmission data can be prevented. Therefore, the data communication device 1 can reliably transmit the transmission data.

The data communication device 1 according to the present embodiment
Uses PHS2 as the transmission means, but is not limited to this. For example, another wireless communication device or a wired communication device may be used. As long as the transmitting means transmits at predetermined slots, substantially the same effects as in the present embodiment can be obtained.

However, when a wireless communication device is used,
The state of the wireless section easily changes due to movement of the communication device. In this case, the transmission speed of a normal slot changes frequently as compared with the case of a wired connection, and it is necessary to perform flow control more frequently. Therefore, the effect of applying the present invention is even greater.

[0066]

As described above, in the data communication apparatus according to the present invention, at the time of flow control in which the number of slots stored in the temporary storage means is increased, the time interval at which the slot generation means generates slots is compared with the normal time. Extend it to the slot
A configuration in which a control means Ru increase the rate of the transmission data occupies.

Therefore, the speed of accumulating slots in the temporary storage can be suppressed without lowering the transmission data generation speed by the data generator. Therefore, there is an effect that a decrease in throughput can be suppressed during flow control.

As described above, in the data communication apparatus according to the present invention, when the number of slots stored in the temporary storage means is increased, the flow is controlled by the slot generation means.
Control means for extending the time interval compared to the normal time and delaying the slot generation by the slot generation means until the transmission data is full of the information amount of the slot.
And is a configuration that.

Therefore, at the time of flow control, the slot generation means can maximize the ratio of transmission data to each slot. Therefore, the transmission speed of the transmission data by the transmission means becomes maximum. As a result, there is an effect that a decrease in throughput can be further suppressed.

As described above, the data communication device according to the present invention further comprises a data terminal device.
Transmits the transmission data generated by each of the slots
And a data generation control means for controlling a speed at which the data terminal device generates transmission data in accordance with the number of slots stored in the temporary storage means.

Therefore, also in the above data communication device, the overflow of the temporary storage means can be reliably prevented. Therefore, transmission data loss due to overflow can be prevented, and transmission data can be transmitted reliably.

Further , the data communication device according to the present invention comprises:
As described above, data generation means for generating transmission data ,
The transmission data is divided, and a slot as a unit at the time of communication is determined.
The slot generating means to be generated, and the generated slot is temporarily
Temporary storage means for storing, and reading a slot from the temporary storage means.
Data communication device having transmission means for transmitting
The number of slots stored in the temporary storage means increases.
During the added flow control, the slot generation means
The time interval for generating the
Slot until the data reaches the full amount of information in the slot.
Control means for delaying slot generation by slot generation means
It is a configuration provided with.

The data communication device according to the present invention is
In addition, the number of slots stored in the temporary storage
Accordingly, the speed at which the data generation means generates transmission data is
This is a configuration including data generation control means for controlling.

The data communication method according to the present invention comprises:
As described above, the transmission data is divided into units for communication.
Slot generation processing for generating a slot to be
Temporary storage processing for temporarily storing data in the transmission buffer device, and
The slot is read from the transmission buffer device and transmitted.
A data communication method including a transmission process.
The number of slots stored in the buffer
-When the control start value is exceeded, the slot generation process
The time interval for generating cuts is extended compared to normal
Control processing to increase the ratio of transmission data to lots
It is a method including.

The data communication method according to the present invention is as described above.
As described above, further, the above-described control processing
Until the amount of information held by
Is a method of delaying the generation of the slot.

The data communication method according to the present invention is as described above.
As described above, the slot generation is performed by the control processing.
Even if the speed of slot generation in processing is reduced,
The number of slots stored in the
When the second flow control start value is exceeded,
The production rate of the transmission data in the data terminal equipment to produce low
This is a method including a data generation control process to be performed.

[Brief description of the drawings]

FIG. 1 illustrates one embodiment of the present invention, and is a block diagram illustrating a main configuration of a data communication device.

FIG. 2 is a flowchart showing an operation at the time of transmission of a flow control device in the data communication device.

FIG. 3 shows a conventional example, and is a block diagram illustrating a main configuration of a data communication device.

FIG. 4 is a block diagram showing another example of the related art and showing a main configuration of a data communication device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 data communication device 2 personal handyphone system (transmission means) 3 data terminal device (data generation means) 4 slot generation device (slot generation means) 5 transmission buffer device (temporary storage means) 7 flow control device (control means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04J 3/00-3/26 H04L 29/00-29/14

Claims (8)

(57) [Claims] 1. Slot generating means for dividing transmission data to generate a slot serving as a unit at the time of communication, temporary storing means for temporarily storing the generated slot, and transmitting means for reading and transmitting the slot from the temporary storing means. In the data communication device having the above, at the time of the flow control in which the number of slots stored in the temporary storage means is increased, the time interval at which the slot generation means generates a slot is extended as compared with a normal time, and
Data communication apparatus characterized by comprising a control means for Ru increase the rate of the transmission data occupies. 2. The transmission data is divided and used as a communication unit.
Slot generating means for generating a slot, and the generated slot
A temporary storage unit for temporarily storing the set, and
Data having transmission means for reading and transmitting a lot
In the communication device, the slot generation unit generates a slot during flow control in which the number of slots stored in the temporary storage unit is increased.
Control means for extending the time interval for performing the slot generation by the slot generation means until the transmission data becomes full of the information amount of the slot as compared with the normal time.
Data communication and wherein the Eteiru. 3. The data communication device according to claim 1 , wherein the data terminal device is
The generated transmission data is transmitted for each slot.
A than, depending on the number of slots the temporary storage means for storing, on
3. The data communication device according to claim 1, further comprising data generation control means for controlling a speed at which the data terminal device generates transmission data. 4. A data generating means for generating transmission data,
The transmission data is divided, and a slot as a unit at the time of communication is determined.
The slot generating means to be generated, and the generated slot is temporarily
A temporary storage means Ru stored, read the slot from the temporary storage means
Data communication device having transmission means for transmitting
In this case, the number of slots stored in the temporary storage means is increased.
During row control, the slot generation means generates slots
Data transmission time by extending the time interval
Until the slot is full of information
Control means for delaying slot generation by the generation means is provided.
A data communication device, comprising: 5. The number of slots stored in said temporary storage means.
Speed at which the data generation means generates transmission data according to
Data generation control means for controlling the
The data communication device according to claim 4, wherein 6. The transmission data is divided into units for communication.
Slot generation processing for generating a slot to be
Temporary storage processing for temporarily storing data in the transmission buffer device, and
The slot is read from the transmission buffer device and transmitted.
A data communication method including a transmission process, wherein the number of slots stored in the transmission buffer device is increased.
When the first flow control start value is exceeded
The time interval for generating slots during processing is
To increase the percentage of transmitted data in slots
A data communication method including a control process. 7. The control process according to claim 1 , wherein the transmission data is a slot data.
Until the amount of information held is full,
7. The method according to claim 6, wherein slot generation is delayed.
Data communication method described above. 8. The slot generation processing according to the control processing.
Even if the speed of generating slots is reduced,
As the number of slots stored in the buffer device increases further,
When the second flow control start value is exceeded, the above transmission data is generated.
Transmission data generation speed at the data terminal device
Billed, characterized in that it comprises a data generation control processing to
Item 8. The data communication method according to item 6 or 7.