JPH10210047A - Data transmission equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the band of a unitary control system without reserving the band at the time when the unitary control system and a feedback system exist together. SOLUTION: When data transmission from a data transmission means 3 if the unitary control system is started, the start of data transmission where the band is secured is reported to a band assurance control means 7. In accordance with this report, the band assurance control means 7 instructs a feedback report means 7a to transmit a feedback report. In response to this instruction, the feedback report means 7a generates and gives contention occurrence information to the feedback report and transmits it to all of data transmission equipments being in the middle of data transmission. A transmission band control means 1a of a data transmission means 1 of the feedback system reduces the use band by the feedback report, and the data transmission means 1 transmits data in the reduced use band.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a data transmission apparatus, and more particularly to contention control for data transmission.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional ATM network 30 to which a client 20 and a server 40 are connected.
1 and a relay device 32 such as a router, a bridge, or a switch. The client 20 starts data transmission to the server 40 at an arbitrary time. If data transmission concentrates on the transmission medium 31 between the relay devices 32 or the transmission medium 31 to the server 40, contention for data transmission occurs.

The occurrence of contention will be described in detail with reference to FIG. Each terminal transmits data via a transmission medium constituting a network. The transmission band indicating the data transmission capacity of the transmission medium is represented by the amount of transmission data per unit time. There is a limit to the transmission band of a transmission medium, and the maximum transmission band (hereinafter, Rmax (bit / sec)) is a fixed and finite value. The bandwidth used for data transmission by each terminal (hereinafter, r (t)) shares the network by dividing and using Rmax. r (t) changes from moment to moment, and when the sum of r (t): Σr (t) is greater than Rmax of the transmission medium, a scramble for a shared band occurs between respective data transmissions. This is called a conflict. Rma
Data requiring a band exceeding x is lost without being transmitted. Therefore, in order to avoid this data loss, control for avoiding contention, that is, contention control is performed.

Next, the conflict control will be described.

[3 Competitive Control Systems] The competitive control system includes:
There are the following three. A transmission medium use band is reserved before data transmission, and within this range, a reservation system using a band (hereinafter, simply referred to as a reservation system) is transmitted without reservation. A feedback method that feeds back to the transmitting terminal and limits the amount of bandwidth used (hereinafter simply referred to as a feedback method) Each data is transmitted based on data transmission control information exchanged between a client and a server before data transmission. Transmission order
A unified control method (hereinafter, simply referred to as a unified management method, which unifiedly controls a band and the like to avoid contention), which has been proposed by the present applicant and is an undisclosed technique.
No. 7949).

[Reservation method and its features] The reservation method will be described below. Usually, the reservation of the bandwidth is performed at the same time when the connection is established. The procedure for establishing a connection is called a call connection procedure. First, a client requests a band by a call connection procedure before data transmission. A call connection is made between the client and the adjacent relay device. A call connection request including a bandwidth reservation request and an identifier (destination identifier) that can specify a connection server is made from a client to a relay station. The relay device that has received the call connection request determines the sum of the bandwidth (ra) requested by the client and the total value (Σri) of the bandwidth currently reserved for the client i (i = 1, 2, 3,...). Is the transmission medium band (Rma
Check if x) is not exceeded.

[0007]

Rmax> @ ri + ra When the bandwidth of the physical medium is not exceeded, it is determined that the requested bandwidth can be secured, and the call connection is returned by returning a call connection response including information on the completion of bandwidth securing. You.

Next, the same processing is performed between the relay station that has established a connection with the client and an adjacent relay station or server determined by the destination identifier. By repeating this processing up to the server, a band can be secured for all the paths from the client to the server.

In the reservation type, when the data transfer is completed, the bandwidths of all the paths secured before the data transmission are released. This is repeated each time data transmission occurs. Therefore, no conflict occurs during data transfer.

[0010] However, if the bandwidth cannot be ensured even with one route, the reservation is not established and there is a problem that data transfer cannot be performed. If the band cannot be secured during the call connection procedure, the call is not established. This is called a call loss. When a call loss occurs, it is not known when the currently transmitting call completes the transmission and releases the reserved bandwidth. Thus, there is no guarantee when the connection will be possible.

By the way, the current LAN service has been developed on the assumption that no call loss occurs between terminals directly connected via a transmission medium, and has been developed. Service cannot be provided. The reservation method has a feature that the bandwidth can be guaranteed, but data transmission of the LAN service cannot be realized due to a call loss.

[Feedback System and Its Features] Next, the feedback system will be described with reference to FIGS. 3 and 4, the first data transmission means 1
, Data transmission is started at an arbitrary timing from the second data transmission means 1 '. At this time, the first data transmission means 1 periodically transmits competition information acquisition data for obtaining feedback information. The ABR (A
RM (Resource Management) used for available Bit Rate service
t) A method using a cell (FIG. 5) is known. RM
The cell uses a CI (Indica) to indicate that a conflict has occurred.
te Congestion) bit. The first data transmission means 1 periodically stores an RM cell in a server,
Or, it transmits to the relay device. The server or the relay device that has received the RM cell displays the occurrence of the conflict in the CI bit only when a conflict has occurred, and returns the CI bit to the first data transmission unit 1.

The contention control means 2 comprises: a data transmission means 1;
The occurrence of contention is detected by monitoring the amount of data transmitted from 1 '. As a means for detecting the occurrence of a conflict, a threshold for judging the conflict is determined in advance. This threshold value can be, for example, a time until a buffer for temporarily storing transmitted data overflows.
When the value exceeds the range of the predetermined threshold value, it is determined that a conflict has occurred. Upon detecting the occurrence of the conflict, the conflict control means 2 transmits a feedback notification to all the data transmitting means 1, 1 'during data transmission. Each time the data transmission means 1, 1 'receives the feedback notification, it reduces the transmission band used for data transmission at a predetermined reduction rate. The contention is avoided by repeating the feedback notification until the data amount monitored by the contention control means 2 falls below the threshold.

[0014] The feedback method that does not make a reservation is used in LAN services because no call loss occurs. In the feedback method, feedback is applied depending on the occurrence state of another data transmission, and the used band is reduced. However, in feedback control, it takes time until a feedback notification is transmitted and the used band is reduced. Therefore, a buffer must be provided in order to avoid loss of received data during the period until the feedback notification is transmitted and the bandwidth used is reduced. Further, since the used band must be reduced by the feedback notification, the band cannot be guaranteed.

[Uniform control method and its characteristic] Next, the unified control method will be described with reference to FIGS. As shown in FIG. 6, each of the data transmission apparatuses in the unified control system has a data transmission unit 3, a data transmission control information generation unit 4, a transmission mode determination unit 5, and a transmission medium use band storage unit 6. 6 and 7, first, the data transmission means (second data transmission means) of the second data transmission device
3 ′ performs data transmission in the band ri specified by the data transmission control device (not shown). The time when the data transmission is completed is defined as Ta. The data transmission means (first data transmission means) 3 of the first data transmission device generates information indicating characteristics of data transmission, and notifies the data transmission control device of the information. The data transmission control device uses a band ri (i = 1, 1) for each data transmission performed at that time.
2,3. . . ) And the total bandwidth Σri, and the time ti (i = 1, 2, 2,
3. . . ), The used band r and the time ta until the next data transmission is completed are obtained. After counting the time ta until the data transmission of the second data transmission device is completed, the data transmission control device transmits a transmission instruction to the first data transmission device so as to start data transmission in the band r. . When receiving the transmission instruction, the data transmission means 3 of the first data transmission device starts data transmission in band r. As described above, even when a plurality of data transmissions are simultaneously requested on the transmission medium, the data transmission can be performed without causing a conflict.

In the unified control system, no data is lost because no conflict occurs. Therefore, there is a feature that it is not necessary to have a buffer for avoiding data loss.
In the unified control method, data transmission control information such as the amount of data is exchanged between the client and the server before the data transmission is started, and the data transmission start time and the used band are centrally managed and controlled based on the data. Therefore, there is a feature that there is no call loss at the time of call connection and a band is guaranteed.

[Problems of the Related Art] In recent on-demand printing services, a large amount of bulk data must be transmitted within a certain period of time. Has become.

By the way, from the above-mentioned features of each competitive control,
A unified control method is used for a LAN service requiring a bandwidth guarantee. However, in general, there are also LAN services that do not require bandwidth guarantee, and these use a feedback method. Therefore, LA using the unified control method
The N service and the LAN service using the feedback method may coexist.

The operation when the unified control and the feedback control coexist will be described with reference to FIGS. 8 and 9, the first and second data transmission means 3,
3 'is for transmitting data in a unified control system, and the third data transmitting means 1 is for transmitting data in a feedback system. Now, it is assumed that the centrally controlled data transmission means 3 is performing data transmission using the band ra. At this time, when the data transmission means 1 under feedback control starts data transmission in the band rb,

[0020]

## EQU2 ## If Rmax <ra + rb (Rmax: maximum bandwidth of the transmission medium), a conflict occurs. In the data transmission using the unified control, since the server or the relay device does not have a buffer, there is a problem that data loss occurs immediately when a conflict occurs. The data loss rl at this time can be obtained from the following equation.

[0021]

Rl = ((ra + rb) -Rmax) × S (S: time of contention) For example, full-color still image data of A4 size is 4
00 dpi (dotper inch), 32 bits /
In the case of the pixel, the size is 64 MBytes, and it takes about 3 seconds even when the data is transmitted in the maximum bandwidth (about 156 Mbps) of the ATM transmission medium. When the data transmission unit 1 under feedback control transmits the data amount transferred via the network with the band rb = 100 Mbps as 200 KBytes, the data loss amount when the transfer of the full-color still image data competes as described above ( rl) is

[0022]

Rl = (156 Mbps + 100 Mbps−1)
56Mbps) × (200KByte ÷ 100Mbps)
s) = 100 Mbps × 1.6 ms = 1.6 Mbps, and the data loss rate due to contention is 10 ⁻² .

The size of data transferred in recent networks tends to increase, and the calculated data loss rate also tends to worsen. As a result, there has been a problem that the band cannot be guaranteed, and services that require the transmission band cannot be realized.

[0024]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when the unified control system and the feedback system coexist, the bandwidth of the unified control system can be reduced without reserving the band. Is intended to guarantee.

[0025]

[Means for Solving the Problems]

[New point of view] Conventionally, in the feedback control, when a conflict occurs, a feedback notification is transmitted to reduce the bandwidth of the transmitting apparatus. However, there is a time delay. Current technology is moving in the direction of how to reduce that delay. In the unified control, data transmission control information such as the data amount is exchanged between the client and the server before the data transmission is started, and the data transmission start time and the band to be used are determined centrally based on the data.
The aforementioned delay is not a problem. The present invention has focused on the fact that the feedback mechanism can be used in a feed-forward manner.

[Specific Means] The unifiedly controlled data transmission device notifies the start of the data transmission by the unified control by transmitting the transmission control information. When receiving the transmission control information, the data transmission control device continues to transmit a feedback notification by using a feedback control mechanism. Upon receiving the feedback notification, the device that follows the feedback control reduces the bandwidth used. Thereafter, the centrally controlled data transmission device starts data transmission.

As described above, it is possible to secure a band for data transmission using unified control and to avoid data loss due to contention.

That is, according to the present invention, in order to achieve the above-mentioned object, prior to data transmission from a non-feedback control type data transmission device to a data reception device, the data transmission control device transmits the data to the non-feedback control type data transmission device. Each time data transmission is performed from the non-feedback control type data transmission device to the data reception device, the data transmission control is transmitted to the data transmission control device prior to the data transmission. Means for notifying information, means for determining data transmission mode from the non-feedback control type data transmitting apparatus based on data transmission control information notified prior to the data transmission, and information on existing data transmission. Means for storing the determined data transmission mode,
Means for instructing transmission of a feedback notification based on the transmission start time of the determined data transmission mode, means for instructing transmission stop of the feedback notification based on the transmission end time of the determined data transmission mode, Means for instructing the non-feedback control type data transmission device to transmit data according to the determined data transmission mode; means for transmitting a feedback notification to the feedback control type data transmission device based on the transmission instruction of the feedback notification; Means for stopping transmission of the feedback notification based on the notification transmission stop instruction; means for instructing control of the data transmission band based on the feedback notification; and setting the data transmission band based on the instruction for controlling the data transmission band. Control means is provided.

In this configuration, when performing non-feedback control type data transmission, a feedback notification is made to the feedback control type data transmission device, and a band for non-feedback control type data transmission can be secured.

Further, the data transmission apparatus having this configuration further includes means for notifying the used band together with the feedback notification transmission instruction before data transmission, means for monitoring the currently used band before data transmission, and Means for determining that the notified used band has been secured based on the obtained used band and the total bandwidth of the transmission medium, a means for notifying the determination result, and a notification of a data transmission instruction triggered by the notification May be provided.

Further, means for storing the receivable data amount by a feedback notification transmission instruction before data transmission to the data transmission device having this configuration, and transmitting the feedback notification by setting the receivable data amount to zero by the feedback transmission instruction Means for rewriting the feedback notice to the stored receivable data amount by a feedback notice transmission stop instruction, and means for instructing transmission corresponding to the receivable data amount when receiving the feedback notice May be provided.

Further, means for storing an available bandwidth in response to a feedback notification transmission instruction before data transmission to the data transmission apparatus having this configuration, and means for transmitting a feedback notification by setting the available bandwidth to zero in accordance with the feedback transmission instruction And means for rewriting and transmitting the feedback notification to the stored usable bandwidth in response to the feedback notification transmission stop instruction, and means for instructing transmission corresponding to the available bandwidth when receiving the feedback notification. It may be.

According to the present invention, in order to achieve the above object, data transmitted from the non-feedback control type data transmitting apparatus prior to data transmission from the non-feedback control type data transmitting apparatus to the data receiving apparatus is provided. A data transmission control device that receives transmission control information and controls data transmission from the non-feedback control type data transmission device, based on the data transmission control information and information on existing data transmission, the non-feedback control type Means for determining a data transmission mode from the data transmission apparatus, means for storing the determined data transmission mode, and means for instructing transmission of a feedback notification based on the transmission start time of the determined data transmission mode When,
Means for instructing the transmission stop of the feedback notification based on the transmission end time of the determined data transmission mode, and means for instructing the non-feedback control type data transmission apparatus to perform data transmission in the determined data transmission mode, Means are provided for transmitting a feedback notification to the feedback control type data transmitting apparatus based on the transmission instruction of the feedback notification, and means for stopping transmission of the feedback notification based on the transmission stop instruction of the feedback notification.

Also in this configuration, when performing the non-feedback control type data transmission, a feedback notification is made to the feedback control type data transmission device, and the band for the non-feedback control type data transmission can be secured.

According to the present invention, in order to achieve the above object, the data transmission notified from the non-feedback control type data transmitting apparatus prior to the data transmission from the non-feedback control type data transmitting apparatus to the data receiving apparatus. A data transmission control device for receiving control information and controlling data transmission from the non-feedback control type data transmission device, wherein the feedback control is performed by transmitting a feedback notification to the feedback control type data communication device based on the data transmission control information; The use band of the mobile communication device is controlled.

Also in this configuration, when performing non-feedback control type data transmission, a feedback notification is made to the feedback control type data transmission device, and a band for non-feedback control type data transmission can be secured.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a data transmission device according to the present invention will be described. FIG. 10 shows a schematic configuration of a data transmission apparatus according to the present invention. In this figure, the data transmission apparatus includes a transmission mode determination unit 5, a transmission medium use band storage unit 6, a band guarantee unit 7, a data transmission control information Generating means 4,
It is configured to include a first data transmission unit 1, a second data transmission unit 3, and the like. Hereinafter, each part will be described in detail.

Transmission Mode Determination Unit 5 The transmission mode determination unit 5 determines the transmission mode such as the data transmission use band and the data transmission start time, and counts up to the determined time. At the determined time, the transmission mode determining means 5 notifies the bandwidth guarantee control means 7 that the data transmission for guaranteeing the bandwidth is started, and urges the bandwidth to be reduced. After that, the second data transmission means (unified control system) 3 is notified of the used band together with the transmission instruction.

Transmission medium used band storage unit 6 The transmission medium used band storage unit 6 stores the used band of each data transmission currently being performed and the total value of the used bands, and the transmission until the end of the transmission of each data transmission. I remember the time.

Band Assurance Control Means 7 The bandwidth assurance control means 7 includes a feedback notifying means 7a, and transmits a feedback notice in response to the notification of the start of data transmission for guaranteeing the band. Further, when notified of the end of the data transmission for guaranteeing the band, the band guarantee control unit 7 stops transmitting the feedback notification.

Data transmission control information generating means 4 The data transmission control information generating means 4 generates a transmission device identifier for identifying the second data transmitting means 3 and data transmission control information such as the amount of data to be transmitted. The state determining means 5 is notified.

First Data Transmitting Means 1 The first data transmitting means 1 performs data transmission by a feedback system, and includes a transmission band control means 1a. The transmission band control means 1a includes a band guarantee control means. 7
When the feedback notification is received from, the bandwidth of data transmission of the first data transmission means 1 is controlled.

Second data transmitting means 3 The second data transmitting means 3 starts data transmission at the designated time and band according to the transmission instruction from the transmission mode determining means 5.

Next, the operation will be described. First, it is assumed that the first data transmission unit 1 performs data transmission by feedback control. At this time, the second
In order to perform data transmission, the data transmission means 3 first notifies a data transmission control device (not shown) of a data transmission request. Then, the data transmission control information generating means 4 generates data transmission control information and supplies it to the transmission mode determining means 5. The transmission mode determining means 5 determines the mode of transmission from the data transmission control information and the information on the band use state stored in the used band storage means 6 of the transmission medium. The second data transmission means 3 performs transmission based on the determined mode. The transmission mode determination means 5 further includes a bandwidth guarantee control means 7 prior to the data transmission of the first data transmission means 1.
To perform the data transmission. The bandwidth guarantee control means 7 sends a feedback notification to the first data transmission means 1 for feedback control based on this notification, and
The bandwidth used by the second data transmission means 3 is secured by reducing the bandwidth used by the data transmission means 1.

[Embodiment 1] Next, an example in which each means of the present invention is actually mounted on an apparatus will be described with reference to FIG. In FIG. 11, parts corresponding to those in FIG. 10 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 11, the data transmission control device 11
Is provided with a data transmission control information generating unit 4, a transmission mode determining unit 5, a transmission medium use band storage unit 6, and a band guarantee control unit 7. The first data transmission device 8 includes a first data transmission unit 1 using a feedback control method. The second data transmission device 9 is provided with a second data transmission means 3 for performing band-guaranteed data transmission by unitary control. The first data transmission device 8 and the second data transmission device 9 transmit data to the data receiving device 10 under the control of the data transmission control device 11. Each unit of the data transmission control device 11 can be provided in the data transmission devices 8 and 9 and the data reception device 10.

Next, the operation of this embodiment will be described. Here, in a network in which a data transmission device 9 that performs data transmission by unitary control and a data transmission device 8 that performs data transmission by feedback control coexist, first, the data transmission device 8 performs data transmission by a feedback method. And on the way,
The operation when the data transmission device 9 under unitary control starts data transmission will be described.

FIG. 12 shows the operation at this time. In FIG. 12, a data transmission control information generating means 4 generates data transmission control information including information of a data transmission identifier (i) for uniquely identifying the data transmitting means 3 and an amount of data to be transmitted (D bit). Is transmitted to the transmission mode determining means 5. The transmission mode determining means 5 includes a data transmission identifier (i) and an amount of data to be transmitted (D bit).
And the band (ra) currently used in the unified control data transfer stored in the used band storage means 6 of the transmission medium.
(In FIGS. 11 and 12, ra = 0 since there is no unified control data transfer) and the data transmission completion time (ta) during the current data transmission, and the used bandwidth r () of the second data transmission. bps) is calculated by the following equation.

[0049]

R = Rmax− (Σri-ra) (Rmax: maximum bandwidth of transmission medium, Δri: total bandwidth used in feedback control) Time required for data transmission based on transmission data amounts D and r t1 (sec) is calculated by the following equation, and is notified to the used band storage unit 6.

[0050]

T1 = D ÷ r + D × E ÷ r (E: Transmission error rate known in advance) Next, counting is performed until the completion time (ta) of the current data transmission. At the determined time, the bandwidth guarantee control means 7 is notified that data transmission for guaranteeing the bandwidth is started.

When the transmission mode determination unit 5 notifies the start of the unified control data transmission, the band guarantee control unit 7
It instructs the feedback notification means 7a (FIG. 10) to transmit a feedback notification. When the feedback notification unit 7a receives the transmission instruction of the feedback notification from the band guarantee control unit 7, the feedback notification unit 7a creates the contention occurrence information (for example, FIG. 5) in the feedback notification, and the first data transmission device 8 during all data transmission. Send to

The transmission band control means 1a of the first data transmission means 1 receives a feedback notification from the feedback notification means 7a and determines a predetermined band reduction rate (dr).
The transmission band (r) is obtained from the data and the currently used band (rb), and the data transmission means 1 is notified of the band.

[0053]

[Mathematical formula-see original document] r = rb.times.dr.
To continue sending.

As a result, the transmission band of the first data transmission unit 1 is reduced, and the band of the second data transmission unit 3 is secured.

After that, the second data transmission means 3 is notified of the band used together with the transmission instruction. The second data transmission means 3 starts data transmission in the notified use band.

On the other hand, after the data transmission of the second data transmission means 3 is started, by counting t1, the second
The data transmission completion time of the data transmission device 9 is detected.
When the data transmission completion time comes, it notifies the bandwidth guarantee control means 7 that the data transmission for guaranteeing the bandwidth has ended. When notified of the end of the unified data transmission from the transmission mode determining unit 5, the bandwidth guarantee control unit 7 instructs the feedback notifying unit 7a to stop transmitting the feedback notification. Feedback notification means 7
When receiving the feedback notification transmission instruction, a stops transmission of the feedback notification.

Even if data transmission is newly started by the feedback method after the data transmission of the bandwidth guarantee is started, a feedback notification is transmitted at the same time as the data transmission of the feedback method is started, and the band is reduced. It is possible to guarantee a band already used by data transmission using unified control.

[Second Embodiment] In the first embodiment, the transmission mode determining means 5 notifies the band guarantee control means 7 of the start of the unified control data transmission, and then notifies the data transmission means 3 of the transmission instruction. By doing so, the bandwidth was guaranteed. However, a conflict may occur depending on the timing.
In other words, this is because data transmission under unitary control is started without confirming that all the bands during data transmission have been reduced.

Therefore, the above problem is solved by adding the following function to the bandwidth guarantee control means 7 of the first embodiment.

FIG. 13 shows the structure of the embodiment. 13, parts corresponding to those in FIG. 12 are denoted by corresponding reference numerals, and detailed description thereof will be omitted.

The transmission mode determining means 5 'counts up to the data transmission completion time (ta).
For the band guarantee control means 7 ', the start of the data transmission for guaranteeing the band is indicated by the band (r
Notify with a).

The band guarantee control unit 7 ′ recognizes that the band has been secured based on the band securing notification, and sends the data transmission unit 3.
To the transmission band together with the transmission instruction.

When the start of unitary control data transmission is notified from the transmission mode determining means 5 ', the bandwidth guarantee control means 7' instructs the feedback notification means 7a to transmit a feedback notification. At this time, the band (ra) used in the unified control data transmission is also notified.

After instructing the transmission of the feedback notification, the bandwidth used for data reception is monitored. As a monitoring means, in a transmission system using fixed-length data (D bit) such as ATM for data transmission, it is possible to obtain a used bandwidth (r (bps)) by a fixed-length data reception interval (t1). It is possible.

[0065]

## EQU8 ## r = D × (1SＤt1) (1S: 1 second) The used band (r) obtained in this way and the unitary control band (ra) notified from the transmission mode determining means. And the maximum band (Rmax) of the transmission medium to confirm whether the band of the unified control can be secured.

[0066]

Rmax ≧ ra + r When the above expression holds, it is determined that the band of the unified control has been secured, and a band securing notification is sent to the transmission mode determining unit 5 ′.

When the end of the data transmission for guaranteeing the bandwidth is notified from the transmission mode determining unit 5 ', the transmission mode determining unit 5' instructs the feedback notifying unit 7a to stop transmitting the feedback notification.

By changing the transmission mode determining means 5 and the bandwidth guarantee control means 7 of the first embodiment to the above means, the data transmission is started after the bandwidth is completely secured, so that no conflict occurs. .

[Embodiment 3] In the first embodiment, the occurrence of contention is notified by a feedback notification, thereby requesting the transmission band control means 1a to reduce the band. In this embodiment, the receivable data is notified by the feedback notification. By setting the amount to zero and not performing data transmission from the first data transmission means 1, the band of data transmission by unitary control is guaranteed.

When instructed to start transmission of the feedback notification, the feedback notification means 7a stores the amount of receivable data set in the feedback notification until then. Feedback notification information with the receivable data amount set to zero is created, and the created feedback notification information is transmitted to all data transmission devices 8 that are transmitting data.

When the transmission end of the feedback notification is instructed, the receivable data amount of the feedback notification information is rewritten to the stored receivable data amount and transmitted to all the data transmitting devices 8 during data transmission. I do.

The transmission band control means 1a instructs the data transmission means 3 to transmit the data amount specified by the feedback notification information.

By changing the means of the first embodiment to the above means, it is possible to guarantee the band of data transmission by the unitary control when the feedback system and the unitary control system coexist.

The amount of receivable data is not zero,

[0075]

[Mathematical formula-see original document] Rmax = Σri-x + ra (Rmax: maximum band of transmission medium, Σri: total sum of bands used in feedback control, ra: band guaranteed by unitary control) To reduce the bandwidth (rd) divided by the number of the first data transmission means 1 currently transmitting, and the remaining bandwidth obtained by subtracting rd from the bandwidth currently being transmitted to the receivable data amount and It is also possible.

[0076]

According to the present invention, a feedback notification is transmitted to a data transmission device other than the unified control system in accordance with the band allocation of the unified control data transmission, and the band used by the device according to the feedback control is reduced. By doing so, a band for data transmission using the unified control is secured. This can avoid conflicts, the yield of data transmission, the data loss rate ^10-2 by competition, can be 10 ^-10 an error rate of the transmission medium.

According to the present invention, a conventional LAN service that does not require a bandwidth guarantee and a LAN service that requires a bandwidth guarantee, such as an on-demand printing service,
It can coexist on a network.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network in which contention occurs.

FIG. 2 is an explanatory diagram of a conflict.

FIG. 3 is a diagram illustrating a configuration of a conventional feedback control method.

FIG. 4 is a diagram for explaining the operation of a conventional feedback control method.

FIG. 5 is a diagram showing a format of feedback notification information.

FIG. 6 is a diagram illustrating a configuration of a unified control system.

FIG. 7 is a diagram illustrating the operation of the unified control method.

FIG. 8 is a diagram illustrating a configuration in which a feedback control system and a unitary control system coexist.

FIG. 9 is a diagram for explaining an operation in which a feedback control system and a unitary control system coexist;

FIG. 10 is a diagram illustrating a specific configuration of the present invention.

FIG. 11 is a diagram illustrating a first embodiment of the present invention.

FIG. 12 is a diagram illustrating the operation of the first example of the present invention.

FIG. 13 is a diagram illustrating a configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Data transmission means (feedback control) 1a Transmission band control means 2 Competition control means 3 Data transmission means (unified control) 4 Data transmission control information generation means 5 Transmission mode determination means 6 Transmission medium used bandwidth storage means 7 Bandwidth guarantee control Means 7a Feedback notification means 8 Data transmission device (feedback control) 9 Data transmission device (unified control) 10 Data receiving device 11 Data transmission control device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichi Yoshimura 430 Nakai-cho Sakaigami-gun, Kanagawa Prefecture Green Tech Nakai Inside Fuji Xerox Co., Ltd.

Claims (6)

[Claims] 1. A data transmission apparatus in which a data transmission control device transmits a data transmission instruction to the non-feedback control type data transmission device prior to data transmission from the non-feedback control type data transmission device to the data reception device, Means for notifying the data transmission control device of data transmission control information prior to the data transmission each time data transmission is performed from the non-feedback control type data transmitting device to the data receiving device; and Data transmission control information, based on information on existing data transmission, based on the means for determining the data transmission mode from the non-feedback control type data transmission device, and means for storing the determined data transmission mode, Feedback is performed based on the transmission start time of the data transmission mode determined above. Means for instructing transmission of a feedback notification, means for instructing to stop transmission of a feedback notification based on the transmission end time of the determined data transmission mode, and the non-feedback control for data transmission according to the determined data transmission mode. Means for instructing the type data transmission device; means for transmitting a feedback notification to the feedback control type data transmission device based on the transmission instruction for the feedback notification; and transmission of the feedback notification based on the transmission stop instruction for the feedback notification. Means for instructing control of the data transmission band based on the feedback notification, and means for controlling the data transmission band based on the instruction for controlling the data transmission band. . 2. A means for notifying a used band together with a feedback notification transmission instruction before data transmission, a means for monitoring a currently used band before data transmission, and a method for monitoring a used band and a transmission medium obtained based on the monitoring result. 2. The apparatus according to claim 1, further comprising: means for judging that the notified use bandwidth has been secured by the total bandwidth; means for notifying the judgment result; and means for notifying a data transmission instruction in response to the notification. Data transmission equipment. 3. A means for storing a receivable data amount by a feedback notification transmission instruction before data transmission, a means for sending a feedback notification with the receivable data amount being zero by the feedback transmission instruction, and a feedback notification transmission stop instruction. 2. The data according to claim 1, further comprising: means for rewriting and transmitting a feedback notification to the stored receivable data amount; and means for instructing transmission corresponding to the receivable data amount when receiving the feedback notification. Transmission equipment. 4. A means for storing an available bandwidth in response to a feedback notification transmission instruction before data transmission, a means for transmitting a feedback notification with the available bandwidth set to zero in accordance with the feedback transmission instruction, and a storage in response to a feedback notification transmission stop instruction. 2. The data transmission apparatus according to claim 1, further comprising: means for rewriting and transmitting the feedback notification to the available bandwidth set; and means for instructing transmission corresponding to the available bandwidth when receiving the feedback notification. 5. A method for receiving data transmission control information notified from the non-feedback control type data transmission device prior to data transmission from the non-feedback control type data transmission device to the data reception device, and receiving the data transmission control information from the non-feedback control type data transmission device. A data transmission control device for controlling data transmission of the data transmission control information, and a means for determining a data transmission mode from the non-feedback control type transmission device based on information on existing data transmission; Means for storing the determined data transmission mode; means for instructing transmission of a feedback notification based on the transmission start time of the determined data transmission mode; and based on the transmission end time of the determined data transmission mode. Means for instructing to stop sending the feedback notification, and Means for instructing the non-feedback control type data transmission device to transmit data in a data transmission mode, means for transmitting a feedback notification to the feedback control type data transmission device based on the transmission instruction for the feedback notification, Means for stopping transmission of the feedback notification based on the transmission stop instruction. 6. A method for receiving data transmission control information notified from the non-feedback control type data transmission device prior to data transmission from the non-feedback control type data transmission device to the data reception device, and receiving the data transmission control information from the non-feedback control type data transmission device. A data transmission control device that controls data transmission, wherein a feedback notification is transmitted to a feedback control type data communication device based on the data transmission control information to control a band used by the feedback control type data transmission device. Data transmission control device.