JPH06132862A - Used extent parameter control system, - Google Patents

Abstract

PURPOSE:To enable high-accuracy UPC control with a small scale hardware by utilizing a stepwise change of transmission speed at every unit time for an output traffic characteristic to control delay fluctuation compensation. CONSTITUTION:Since an average of transmission speed is included in the processing contents of delay fluctuation compensation to use information showing a number x1 of input cells at every unit time TC, a transmission speed is outputted at every TC as stepwise traffic. When a window T1 is the integer multiple of TC, the fluctuation of input traffic at the time of continuously sliding the T1 is turned to a diagonal graph. Therefore, it is enough to monitor the number of input cells at certain time when an end point comes to the partitioning position of TC. When the T1 is not the integer multiple of TC, the T1 and the x1 can be converted, and the number of cells is calculated by using a conversion formula so as to be handled similarly to the case that the T1 is the integer multiple of TC. Thus, high-accuracy UPC control is enabled with the small scale hardware.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a usage parameter control (UPC: Usage Parameter) for protecting resources of a satellite TDMA communication network and a subsequent terrestrial network.
er Control).

[0002]

2. Description of the Related Art A satellite system consisting of a transmitting / receiving earth station and a communication satellite interconnects a plurality of scattered earth stations.
It can be used as an exchange in a terrestrial network or as a subscriber line terminating device. At this time, the asynchronous transfer mode (AT
In order to protect network resources, a switch or the like in a terrestrial ATM network using M) monitors user traffic, that is, usage parameter control (UPC: UsP).
The age Parameter Control) is performed.

UPC is carried out by a user with a declared parameter that defines the traffic characteristics of the user when setting up a line. This parameter is, for example, a set of the maximum value x0 of the number of cells input in the minute time interval T0 for defining the local maximum transmission rate, and a relatively long time interval for defining the average transmission rate. It is composed of a set of maximum value x1 of the number of cells input in T1.

The UPC system includes (1) LB (Lea
ky Bucket) method, (2) T-x method, (3) DB
(Dangerous Bridge) method has been proposed. FIG. 5 shows a conceptual diagram of a conventional UPC system.

FIG. 1A shows the LB method, FIG. 1B shows the Tx method,
(C) shows the DB method. In the figure, 501,
504 and 505 are input cell strings, 502 is a buffer,
Reference numeral 503 indicates an output cell string.

In the LB method of (a), the input cell string 5
01 is temporarily stored in the buffer 502, and this buffer 5
From 02, it is output like an output cell row 503 at equal intervals so as to be equal to the average transmission rate x1 / T1. The UPC function is realized by monitoring the number of cells accumulated in the buffer 502 and monitoring so as not to exceed the defined number of cells x1 [1- (x1 / T1) / (x0 / T0)]. There is.

The Tx method of (b) counts the number of input cells for each window set in the T1 cycle for the input cell sequence 504. Then, by monitoring the cells input in T1 so as not to exceed X1, UP
The C function is realized.

In the case of the DB method of (c), the input cell string 505
A window having a time width T1 is set for each input cell, and the UPC function is realized by monitoring the number of input cells within the time width T1 so as not to exceed x1.

On the other hand, in the connection between the terrestrial ATM network and the satellite TDMA line, the delay fluctuation generated in the satellite TDMA line becomes a problem. Currently, the present inventor has proposed a method of transmitting information about a cell transfer interval at the time of cell input in a form separated from the cell and compensating for the deterioration of transmission quality on the basis of the information about the cell transfer interval on the receiving earth station side. It is disclosed in the specification attached to Japanese Patent Application No. 20077.

FIG. 3 shows the delay fluctuation compensation method. In the figure, 301 is an input cell sequence to the transmitting station, 302 is T
DMA burst, 303 represents an output cell string from the receiving station side. The input cell sequence 301 to the transmitting station is divided at every unit time Tc which is determined by the required quality of delay fluctuation, and the number N of user information cells input at this time Tc is counted.

In this case, N is 5. T
Information of the number of cells is stored in the DMA burst 302 together with the information cells, and the receiving station side changes the cells to Tc within this time Tc.
/ N interval for average distribution and transmission station side output cell sequence 303
Output in the form of. With the above operation, the maximum value of delay fluctuation can be controlled to Tc.

In this system, when a transmission code error occurs, or when an excessive number of cells are input on the transmitting earth station side, information on the number of cells generated at the receiving earth station and the number of cells actually received. How to prevent the mismatch of
It is disclosed in the specification attached to Japanese Patent Application No. 50779 of 1992 by the present inventor.

FIG. 4 shows the structure of the ATM / TDMA conversion buffer section in the method of preventing the mismatch of the numbers of cells actually received. In the figure, 401 is a switch unit, 402 is a VPI / VCI table, 403 is a cell number counter, 404 is a buffer memory, 405 is a cell input / output control circuit, 406 is a selector, 407 is a TDMA burst configuration map, and 408 is the number of cells. The information preparation circuit is shown.

The input cell is read by the switch unit 401 by reading the VPI or VCI portion in which the cell destination information included in the header portion of the cell is recorded, and by referring to the VPI / VCI table 402, it is separated for each call. . The cells separated for each call are counted by the cell number counter 403,
The cell number information creation circuit 408 collectively outputs the cell number information as cell transfer timing information.

On the other hand, the information cell is temporarily stored in the buffer memory 404.
The selector 406 is switched by the TDMA burst configuration map 407 that is stored in the TDMA frame and manages the burst configuration in the TDMA frame, and the cell is transmitted from the buffer memory for each TDMA burst. The cell input / output at this time is managed by the cell input / output control circuit 405, and after the number of cells accommodated in the buffer memory is grasped, if there is an excessive input of cells, the excess can be discarded.

[0016]

SUMMARY OF THE INVENTION In the method disclosed in the above-mentioned 1993 patent application No. 200765 or 1992 patent application No. 50779, the UPC equivalent to the LB method is obtained by temporarily buffering an input cell. Control is realized. However, the LB method and the T-x method have a problem that not all traffic states that are not allowed by the declared parameters can be detected.

On the other hand, a DB that can be executed by UPC with high accuracy
The method has a problem in that a large-capacity buffer is required in a form proportional to the value of x1 and the hardware scale becomes large for a large x1.

The present invention has been made to solve the above problems, and has a high accuracy of UPC for constructing a comprehensive network including a terrestrial network and a satellite system and a hardware scale. The purpose is to provide a method that requires a small size.

[0019]

According to the present invention, the above problems can be solved by the means described in the "Claims". That is, the present invention requires the transmitting earth station to compensate for the delay fluctuation of the ATM cell generated between the transmitting and receiving earth stations in the satellite TDMA line connected to the terrestrial ATM communication network using the asynchronous transfer mode (ATM). The number N of user information cells input in a unit of a predetermined time Tc determined by the transmission quality is counted, the information on the number of cells is transmitted to the receiving earth station, and the receiving earth station uses the information on the number of cells for each Tc. In the satellite communication system for transmitting cells based on the average cell interval Tc / N, among the parameters that the transmitting earth station or the receiving earth station declares to define its own traffic characteristics when the user sets up the line, A means for obtaining the value of a parameter that defines the average transmission rate by the maximum number of cells x1 that can be input in a relatively long time T1, and the value of the parameter and a predetermined T A means for obtaining a time T1 ′ represented by the product of a minimum integer value m equal to or greater than T1 / Tc and Tc, and a means for obtaining the number of cells x1 ′ that are allowed to be input within the time T1 ′. The number of cells input within the time T1 ′ starting from the delimiter position of the unit time Tc at which delay fluctuation compensation control is performed is calculated as the time interval T.
A means for obtaining while shifting by c, and a means for monitoring whether or not the output traffic from the satellite circuit satisfies the traffic conditions defined by the above-mentioned declared parameters by comparing the number of cells with x1 ′ in order It is a usage parameter control method.

[0020]

The traffic input to the transmitting earth station is continuous for the high-speed call that is the target of the terrestrial ATM network due to the compensation process of the delay fluctuation generated in the satellite TDMA circuit in the connection between the terrestrial ATM network and the satellite TDMA circuit. If an error of about one cell that occurs at the boundary of the time interval Tc is allowed, the transmission speed is output as stepped traffic that changes at the boundary of Tc.

Therefore, when T1 is an integral multiple of Tc, T1 when the T1 window is continuously slid
The time variation of the input traffic volume into the window is Tc
The graph is a line-shaped graph in which the slope changes depending on the break position. That is, the maximum value in the time variation of the input traffic amount into T1 always comes to the position where Tc is delimited. Therefore, it is sufficient to monitor the number of input cells only at the time when the end point comes to the break position of Tc.

On the other hand, T1 is a parameter that defines the average transmission rate, so it is considered to be sufficiently larger than Tc (several ms). Therefore, when T1 is not an integral multiple of Tc, it can be converted from (T1, x1) to (T
1 ', x1'). Where T1 'is T1
/ Tc is selected such that T1 ′ = m × Tc for a minimum integer m equal to or more than Tc.

At this time, for example, as a conversion formula, x1 '=
By using x1 × (T1 ′ / T1), x1 ′ can be obtained, and it can be handled in the same manner as when T1 is an integral multiple of Tc. As described above, it is sufficient to monitor the number of input cells only at the time when the endpoint comes to the break position of Tc, and the DB method can be realized with a simple configuration.

Here, x1 'is used as a conversion formula of x1'.
Although the case where 1 ′ = x1 × (T1 ′ / T1) is used has been described, it is generally possible to use other conversion formulas.

As described above, the UPC according to the present invention
The method makes it possible to realize UPC with the same accuracy as the DB method with a simple configuration by performing monitoring at a specific phase. In addition, the Tc required for the UPC method in the present invention
The function of counting the number of cells for each is provided by the satellite TD on the terrestrial ATM network.
It can be shared with the function of counting the number of cells for each Tc, which is necessary for the compensation method of the delay fluctuation that occurs when the MA line is connected. Therefore, when applying to the satellite TDMA system, it is not necessary to newly add special hardware.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of application of the UPC method by the DB method to the traffic after the delay fluctuation compensation processing. The same figure (a)
Shows traffic in which the transmission rate changes stepwise for each Tc due to delay fluctuation compensation processing, and FIG. 11B shows the time variation of the traffic amount input to the T1 window when the output traffic is regarded as a continuous signal. There is.

In FIG. 3A, the delay fluctuation compensation using the information of the number of input cells for each Tc is the same as the processing content of Tc.
Includes averaging of transmission rates for each. Therefore, the transmission rate is output as stepped traffic that changes at the boundary of Tc. However, since the transmission rate in the terrestrial ATM network is defined by the intervals of discontinuous cells, the transmission rate needs to be handled differently from the case of continuous signals in circuit switching.

However, a high-speed call, which is a target of the terrestrial ATM network, does not pose a problem except for an error of about one cell which occurs at the boundary between successive time intervals Tc. Figure 1 above
If T1 in (a) is an integer multiple of Tc, then T1
The time variation of the input traffic volume into the T1 window when one window is continuously slid is shown in FIG.
As shown in (b), the graph becomes a line-shaped graph in which the gradient changes at the break position of Tc.

That is, the maximum value in the time fluctuation of the input traffic amount into T1 always comes to the delimiter position of Tc. Therefore, it is sufficient to monitor the number of input cells only at the time when the end point comes to the break position of Tc. If T1 is not an integral multiple of Tc, T1 is a parameter that defines the average transmission rate, and therefore Tc (several m
It is considered to be sufficiently large with respect to

Here, since Tc is a prescribed value of delay fluctuation as described above, considering image media and the like, it is several ms.
It will be about. Therefore, (T1, x
It is possible to convert from 1) to (T1 ', x1'). Here, T1 'is T1' =
It is selected so that m × Tc.

Therefore, for example, as a conversion formula, x1 '=
By using x1 × (T1 ′ / T1), x1 ′ can be obtained and can be handled in the same manner as when T1 is an integer multiple of Tc. As described above, it is sufficient to monitor the number of input cells only at the time when the end point comes to the break position of Tc, and the DB method can be easily realized.

FIG. 2 shows an embodiment of the present invention for specific traffic. In the figure, 201 is cell interval information, 202 is an output cell sequence, and 203 to 208 are first to sixth cells.
A T1 'window is shown.

In this embodiment, T1 '= 3.Tc, x
1 '= 16. Number of input cells Nj in the j-Tc section (where j is an integer) measured at the transmitting earth station
By adding the (cell interval information 201) for consecutive m (3 in this embodiment) intervals, ΣNj = 14 in the case of the first T1 ′ window 203, ΣNj = 16 in the case of the second T1 ′ window 204, and the In the case of the 3T1 ′ window 205, ΣNj = 17, the fourth T1 ′ window 20
In the case of 6, ΣNj = 16, in the case of the fifth T1 ′ window 207, ΣNj = 12, in the case of the sixth T1 ′ window 208, ΣNj = 12.

UPC is executed by comparing the input traffic amount for each T1 'window with x1'.
In this embodiment, ΣNj in the third T1 ′ window 105
= 17, which exceeds x1 ', and excessive input traffic can be detected.

[0035]

As described above, according to the present invention, when the terrestrial AM communication network and the satellite TDMA line are connected, the delay fluctuation is compensated, so that the output traffic characteristic is controlled for the delay fluctuation compensation. Utilizing the fact that the transmission rate changes stepwise for each unit time Tc, UPC control equivalent to the highly accurate DB method as UPC control is performed with respect to the phase starting from the break position of the control unit Tc for delay fluctuation compensation. It is possible to realize it by simple control by providing only a window. Further, most of the functions required for implementing the present invention are included in the circuit for performing delay fluctuation compensation, so that there is an advantage that the functions can be realized without adding a large amount of new hardware.

[Brief description of drawings]

FIG. 1 D for traffic after delay fluctuation compensation processing
It is a figure which shows the example of application of the UPC system by B method.

FIG. 2 is a diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a conventional delay fluctuation compensation method.

FIG. 4 is a diagram showing an example of a configuration of a conventional ATM / TDMA conversion buffer unit.

FIG. 5 is a diagram illustrating a conventional UPC method.

[Explanation of symbols]

 201 Cell Interval Information 202, 503 Output Cell Sequence 203-208 Window 301 Input Cell Sequence to Transmitting Station 302 TDMA Burst 303 Output Cell Sequence from Receiving Station Side 401 Switch Unit 402 VPI / VCI Table 403 Cell Number Counter 404 Buffer Memory 405 Cell input / output control circuit 406 Selector 407 TDMA burst configuration map 408 Cell number information creation circuit 501, 504, 505 Input cell string 502 Buffer

Claims (1)

[Claims] 1. A request transmission is made at a transmitting earth station in order to compensate for a delay fluctuation of an ATM cell generated between a transmitting and receiving earth station in a satellite TDMA line connected to a terrestrial ATM communication network using an asynchronous transfer mode (ATM). The number N of user information cells input in a unit of Tc, which is determined by quality, is counted, and the information on the number of cells is transmitted to the receiving earth station. In the satellite communication method for transmitting cells based on the average cell interval Tc / N, the transmitting earth station or the receiving earth station compares among the parameters declared by the user to define the traffic characteristics of the user when setting the line. Means for obtaining the value of a parameter that defines the average transmission rate by the maximum number of cells x1 that can be input during a relatively long time T1, and the value of the parameter and a predetermined Tc are compared. By comparing,
The means for obtaining the time T1 ′ represented by the product of the minimum integer value m greater than T1 / Tc and Tc, the means for obtaining the number of cells x1 ′ that can be input within the time T1 ′, and the delay fluctuation compensation control are A means for obtaining the number of cells input within the time T1 ′ starting from the delimiter position of the unit time Tc, which is shifted by the time interval Tc, and the output traffic from the satellite line by sequentially comparing the number of cells with x1 ′. And a means for monitoring whether or not the traffic condition defined by the above-mentioned declared parameter is satisfied, and the usage parameter control method.