JPH0121655B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traffic control system that can perform traffic control with an economical configuration in a circuit switched network using satellite lines, particularly in a telephone network.

In general, communication networks such as telephone networks are designed to meet a certain level of quality for normal traffic.
The switching equipment and line equipment are designed. but,
In recent years, in telephone networks, inquiries related to disasters,
A situation arises in which calls for visits, etc. concentrate on a specific destination, and a load far exceeding the designed traffic is added to the network. Under these circumstances, the network equipment is insufficient compared to the added traffic, and the number of incomplete calls increases, resulting in a significant drop in network efficiency, which may lead to network congestion and even paralysis. . For this reason,
Traffic control is required to prevent network congestion and maintain the network's ability to communicate. These situations do not change in any way even in circuit-switched networks using satellite links.

In the conventional traffic control method, for example, a traffic control center having a traffic control device and each exchange are connected via a dedicated line, a monitoring device of each exchange monitors the congestion of the line and the exchange, and the monitoring information is transferred to the dedicated There is a system in which the data is transferred to the traffic control device via a line, and the traffic control device issues regulations and other commands to each exchange. Since it is necessary to install a conventional method, it has the drawback of requiring a large amount of cost.

The present invention has improved the above-mentioned drawbacks, and its purpose is to enable traffic control to be performed with an economical configuration in a line switching network using satellite lines.

In order to achieve this object, the present invention relates to a system in which a common signal line for transferring a connection signal for controlling call connection is provided in a satellite line in a line switching network using a satellite line. The number of calls for each region and the number of completed calls for each region of calls via the satellite line are counted by monitoring the common signal line, and the number of calls for each region and the number of calls completed for each region are counted at least one specific satellite terminal station of A traffic measuring unit is provided that calculates the incomplete rate for each area based on the number of calls, and the restricted ground information and the restricted rate are obtained based on the incomplete rate for each area calculated by the traffic measuring unit, and the information is connected to the specific satellite terminal station. In the switching equipment that is used, the call is restricted based on the restriction destination information and the restriction rate, and a traffic control signal consisting of the restriction destination information and restriction rate is transferred to the exchange of the circuit switching network, The exchange is configured to receive the traffic control signal and control calls based on the traffic control signal.

Examples will be described in detail below.

FIG. 1 is an explanatory diagram of an embodiment of the present invention, in which the method of the present invention is applied to a telephone network using a satellite line. In the figure, 1 is a satellite, 2 to 4 are satellite lines, 5 to 7 are satellite terminal stations on the ground, 8 to 17 are exchanges, and 20 to 29 are terrestrial lines. There are two types of satellite lines: a fixed allocation method in which a satellite line is fixedly allocated to each satellite terminal station, and a variable allocation method in which a satellite line is allocated at the time a call occurs; Intelsat's SPADE (Single channel per
carrier PCM multiple Access Demand
As the SPADE method is well known, this embodiment will explain the case where the SPADE method is applied. Regarding the SPADE method,
For example, "Electronic Engineering Progress Series 8, Satellite Communications"
(published by Corona Publishing) is described in detail.

Figures 2A to 2D are explanatory diagrams of the SPADE method,
Figure A is a frequency allocation diagram of the SPADE system, where the horizontal axis represents the frequency, 30 is the common signal line,
31 to 33 are audio lines. Common signal line 3
0 performs relay transmission of signals necessary for requesting a line, connecting a call, disconnecting a call, etc., and all satellite terminal stations share the common signal line 30 in a time-division manner. Further, FIG. 3B is a diagram showing the signal configuration of the common signal line 30, in which the horizontal axis represents time, 40 is a reference burst, and 41 to 43 are data bursts. Data bursts 41-43 are exclusively assigned to each satellite terminal. Further, FIG. 3C is a diagram showing the signal structure of data bursts 41 to 43 of the conventional system, in which 50 is a header, 51 is a signal unit, and 52 is a data parity. Further, D in the figure shows an example of the signal structure of data bursts 41 to 43 in the system of the present invention, and 53 is a traffic control signal channel, and the same reference numerals as in C in the figure represent the same parts. ing.

In FIG. 1, for example, a call from the exchange 11 to the exchange 15 is sent to the exchange 15 via the land line 22, the exchange 8, the land line 20, the exchange 9, and the land line 26 when the land line 20 is free. Receive a call.

In addition, when the terrestrial line 20 is blocked, the exchange 8 transfers the call from the exchange 11 to the satellite terminal station 5. As a result, the satellite terminal station 5 first acquires, for example, a vacant voice line 32, and then Voice line number captured by
A connection signal consisting of a dial number, a destination station number (in this case, the terminal station number assigned to the satellite terminal station 6), etc. is sent to each satellite via the satellite 1 using a data burst assigned to the satellite terminal station 5. Send to terminal stations 6 and 7. Each satellite terminal station 5 to 7 has a common signal line 30
When the satellite terminal station 6 detects a call from the satellite terminal station 5, it transfers the call to the exchange 9, which seizes the terrestrial line 26 and transfers the call to the exchange 15. When the subscriber responds, a response signal is transferred in the opposite direction along the call connection path to the exchange 11, and is used for control such as starting billing. In addition, if the land line 26 is blocked after a call arrives at the exchange 9, the exchange 9 connects the call to the exchange 15 to the busy tone trunk, or sends the call to the exchange 8 as a lost call. Notify me of something.

These response signals and call loss signals are transferred via the common signal line 30 mentioned above, so if the common signal line 30 is monitored, the call connection process for all calls via the satellite line can be monitored. You can know. The present invention utilizes this fact to measure the incomplete rate of calls via satellite lines for each location, and performs traffic control based on the measurement results. Note that the non-completion rate for each location can be measured at any satellite terminal station, but it is sufficient to measure it at any one of the satellite terminal stations.

FIG. 3 is a block diagram of a specific satellite terminal station (in this case, for example, satellite terminal station 7) that has a function of measuring the non-completion rate for each destination, and an exchange 10 connected thereto, and 60 is a communication path. 61 is a central processing unit, 62 and 63 are call trunks, 64 is an information line, and 65 is a line connection part, which is the call trunk 6.
It controls the interface between the exchange 10 and the satellite terminal station 7, such as extracting connection signals of dialed numbers from 2 and 63, and 66 is an audio channel section that controls echo canceller and demultiplexing.
68 is a transmitting/receiving unit including a satellite antenna, 69 is a terminal station control device that controls reception of calls addressed to the local station and transmission control of calls originating from the local station, 70 is a traffic measurement unit, and 71 is a control device. 69, information line between traffic measurement units 70; 72, traffic measurement unit 7;
0 is an information line between the line connection section 65; 73 is an information line between the control device 69 and the line connection section 65; FIG. 4 is a block diagram showing the configuration of the traffic measurement unit 70, in which 80 is a memory to which addresses are assigned corresponding to the audio lines 31 to 33, 81 is a memory read/write circuit, and 82 is a memory for each destination. 83 is an arithmetic circuit for calculating the non-completion rate for each destination; 84 is a ground field in the memory 80; 85 is a response field in the memory 80; 86 is a memory in the memory 82. Call number field 87 is the completed call number field in memory 82.

For example, suppose that a call is sent from the exchange 11 to the exchange 15 via the terrestrial line 22, the exchange 8, the satellite terminal 5, and the satellite line 2. In this case, the satellite terminal station 5 connects the captured voice line number (in this case, it is assumed that the voice line with line number N is captured), dial number, destination station number, etc., as described above. The signal is transmitted in a data burst assigned to the satellite terminal station 5.

The satellite terminal station 7 having the configuration shown in FIG. 3 monitors all data bursts 41 to 43 with a control device 69, and when detecting the occurrence of a call from the exchange 11 to the exchange 15, the control device 69 The destination number of the call (in this case A) is determined based on the dialed number, and then the address corresponding to the voice line number N in the memory 80 is sent to the memory read/write circuit 81 via the information line 71. Instruct #X to write the destination number A of the call. Thereby, the memory read/write circuit 81 writes the destination number A into the destination field 84 of address #X. When the call arrives at the exchange 15 and the subscriber answers, the response signal is transferred in the reverse direction along the call connection path to the exchange 11, as described above. Control device 6 of satellite terminal station 7
9 detects this response signal and instructs the memory read/write circuit 81 via the information line 71 to store the fact that the response signal has been received in the response field 85 of the memory 80. As a result, the memory read/write circuit 81 reads the contents of address #X,
For example, the response field 85 is set to "1" and written to address #X again.

When detecting the end of the call, the control device 69 instructs the memory read/write circuit 81 via the information line 71 to update the number of calls for each destination and store it in the memory 82. As a result, the memory read/write circuit 81 reads the contents of the address #X in the memory 80 and learns the destination number A from the destination field 84, and then the contents of the address #Y corresponding to the destination number A in the memory 82. and call number field 8.
6 +1 to the number of calls stored in address #X, and further determines the response field 85 read from address #X.
If the response field 85 is "1", the number of calls stored in the number of completed calls field 87 is incremented by one. If the response field 85 is “0”, the call is an incomplete call, so the number of completed calls field 87
There is no need to update. After updating the number of calls and the number of completed calls, the memory read/write circuit 8
1 stores these data at address #Y of memory 82.
At the same time, the address #X of the memory 80 is cleared. That is, through the above processing, the number of calls and the number of completed calls for each destination are sequentially stored in the memory 82.

The arithmetic circuit 83 reads the number of calls for each destination and the number of completed calls stored in the memory 82 at regular intervals, calculates the non-completion rate for each destination based on these, and zeros the contents of the memory 82. This will reset it to . The non-completion rate for each region calculated by the arithmetic circuit 82 is transferred to the central processing unit 61 of the exchange 10 via the information lines 72 and 64, and the central processing unit 61 examines the non-completion rate for each region and sets the regulation activation threshold. If there is a destination that exceeds the regulated destination, the regulated destination and the regulated rate are determined, calls are restricted based on the regulated destination information and the regulated rate, and a traffic control signal consisting of the regulated destination information and the regulated rate is transmitted. Information line 6
4 and 73 to the control device 69 of the satellite terminal station 7. Note that the restriction rate y may be set to, for example, y=kx (k is a coefficient), where x is the non-completion rate by region.

The control device 69 of the satellite terminal station 7 is the central processing device 6
When the traffic control signal is transferred from the satellite terminal station 7, the traffic control signal is transferred to the traffic control signal channel 53 shown in FIG. Send on 9th. The signal is received by the transmitting/receiving section 68 of each satellite terminal station 7, and is sent to the control device 69 and the information line 7.
3. The data is supplied to the central processing unit 61 via the line connection section 65 and the information line 64. And each exchange 8,
9 regulates calls based on traffic control signals. Since the call regulating means in the exchange is well known, a description thereof will be omitted. And each exchange 8,
9 regulates calls based on traffic control signals.

In this way, the exchanges 8 to 10 restrict calls to destinations with a high failure rate for each destination, that is, calls to destinations where calls are concentrated and there is little prospect of receiving calls, thereby reducing network congestion. It can be prevented. This regulation will reduce the non-completion rate by region,
When the release threshold is reached, the exchange 10 sends a release signal to the satellite terminal station 7, and the satellite terminal station 7 transmits the release signal to each exchange 8, 9 via the traffic control signal channel 53, thereby canceling the restriction. Instruct.

In the embodiment, the traffic control signal is transferred to the exchanges 8 and 9 via the traffic control signal channel 53, but it is of course possible to transfer it via a dedicated terrestrial line. It is. Also, from exchange 10 to exchanges 11 to 17,
Of course, it is also possible to transfer the traffic control signal using a terrestrial leased line and regulate calls at the exchanges 11 to 17.

In addition, in the embodiment, one specific satellite terminal station has the function of measuring the non-completion rate for each location.
Specific satellite terminal station and other satellite terminal stations or exchanges 11-1
Of course, if the distance between the specific satellite terminal stations and the satellite terminal station 7 is long and transfer of the traffic control signal is costly, the specific satellite terminal stations may be disposed in a geographically dispersed manner. Furthermore, in the embodiment, the control target and control rate are determined by the central processing unit 61 of the exchange 10, but if the control device 69 of the satellite terminal station 7 has sufficient processing capacity, the control device Of course, it is also possible to do this with 69.

Furthermore, in the embodiments, the satellite line has been explained using the SPADE method, but the present invention is not limited to this, and it goes without saying that a fixed allocation method may also be used. If a traffic control signal channel 53 for transferring control signals is provided in the satellite line, traffic control can be performed in the same manner as in this embodiment. Further, in the embodiment, the traffic control signal channel 53 is provided in addition to the signal unit 51, but the traffic control signal may also be transferred by the signal unit 51. In this case, the transfer of traffic control signals and the transfer of line connection signals are mixed, but since the traffic control signal traffic is small, problems such as overloading the line connection signals do not occur. Further, the present invention can be applied to various circuit switching networks such as facsimile switching networks and data switching networks in addition to telephone networks.

As explained above, the present invention provides at least one specific satellite terminal station among the satellite terminal stations (satellite terminal station 7 in the embodiment) with a traffic measurement unit that calculates the non-completion rate for each location. Based on the established and calculated non-completion rate for each area, a traffic control signal consisting of restricted area information and restriction rate is created, and the traffic control signal is transferred to each exchange. There is no need for a monitoring device or a transfer link from an exchange to a traffic control device, so there is an advantage that traffic control can be performed with an economical configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
Figures A to D are explanatory diagrams of the SPADE system, Figure 3 is a block diagram showing the configuration of a specific satellite terminal station and exchange according to an embodiment of the present invention, and Figure 4 is a traffic measurement unit 70.
FIG. 2 is a block diagram showing the configuration of FIG. 1 is a satellite, 2 to 4 are satellite lines, 5 to 7 are satellite terminal stations, 8 to 17 are exchanges, 20 to 29 are terrestrial lines,
30 is a common signal line, 31 to 33 are audio lines,
40 is a reference burst, 41 is a data burst, 5
0 is a header, 51 is a signal unit, 52 is a data parity, 53 is a traffic control signal channel,
60 is a communication path switch, 61 is a central processing unit, 6
2, 63 are call trunks, 64, 71, 72, 7
3 is an information line, 65 is a line connection section, 66 is an audio channel section, 68 is a transmitting/receiving section, 69 is a control device, 70
is a traffic measurement unit, 80 and 82 are memories, and 81
83 is a memory read/write circuit, 83 is an arithmetic circuit, 84 is a ground field, 85 is a response field, 86 is a call number field, and 87 is a completed call number field.

Claims (1)

[Claims] 1. Regarding a system in which a common signal line is provided on the satellite line to transfer connection signals for controlling call connection in a circuit-switched network using a satellite line, at least one specific satellite terminal station among the satellite terminal stations is , the number of calls for each region and the number of completed calls for each region of calls via the satellite line are counted by monitoring the common signal line, and the non-completion rate for each region is determined based on the number of calls for each region and the number of completed calls for each region. A traffic measurement unit is provided to calculate the traffic measurement unit, and based on the non-completion rate for each area calculated by the traffic measurement unit, regulated ground information and regulated rate are obtained,
In the exchange connected to the specific satellite terminal station,
The call is restricted based on the restriction destination information and restriction rate, and a traffic control signal consisting of the restriction destination information and restriction rate is transferred to an exchange in the circuit switching network, and the circuit switching network exchange receives the traffic control signal. 1. A traffic control method characterized by receiving a traffic control signal and controlling a call based on the traffic control signal.