JPS6342980B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a satellite line with variable allocation system.
This invention relates to a satellite line allocation control system that prevents traffic pressure on terminal stations and service degradation that occurs when traffic at specific terminal stations increases.

In circuit-switched networks such as telephone networks that use satellite lines, there are two methods of allocating satellite lines between terminal stations on the ground: a fixed allocation method that allocates lines in a fixed manner, and a fixed allocation method that allocates lines variably depending on the occurrence of calls. Although there is a variable allocation method, the variable allocation method is generally used because of its efficiency in lines and its flexibility against traffic fluctuations. In this variable allocation system, even if the actual traffic alternating current pattern varies somewhat from the designed value, the line allocation follows the variation pattern, so the fluctuating traffic can be absorbed. However, if the traffic exchange pattern changes drastically, for example when the traffic between specific terminal stations increases, a large number of lines will be allocated between specific terminal stations, and there will be a shortage of lines for calls between other terminal stations. , call losses between other terminal stations will increase, and connections between other terminal stations will be disturbed due to an increase in traffic between specific terminal stations. In extreme cases, there is a possibility that connections between other terminal stations may become impossible. Additionally, if the number of calls from a specific terminal station increases, lines will be allocated to calls from that specific terminal station, resulting in a shortage of lines for calls between other terminal stations, resulting in significant unevenness of service. become. As described above, while the variable allocation system is flexible in response to traffic fluctuations, it has the disadvantage that extreme traffic fluctuations may result in significant unevenness of service.

In order to solve the conventional drawbacks of the above variable allocation method, the present invention provides a common predetermined number of lines for each terminal station, between each terminal station, etc. that is less than a predetermined value (number of reserved outages). The number of lines (number of reserved and suspended lines) is reserved, and if the number of used lines exceeds a predetermined value, lines are allocated only when there are more vacant lines than the number of reserved lines. Explain.

Figure 1 is an example of a telephone network using a variable allocation satellite line, where 1 is a satellite, 2, 3, and 4 are satellite lines, 5, 6, and 7 are terminal stations on the ground, and 8, 9, and 10 are terminal stations on the ground. is an exchange. Variable allocation control methods include a distributed control method in which line allocation is performed at each terminal station, and a centralized control method in which line allocation is performed all at once in a specific terminal station. Although the present invention is applicable to either method, the centralized control method will be explained as an example.

Figure 2a shows an example of frequency allocation in the FDM multiple access system, where the horizontal axis is the frequency, 30 is the common signal line,
31, 32, and 33 are audio lines. The common signal line 30 is a line for relaying and transmitting signals necessary for requesting a line, connecting and disconnecting a call, etc., and all terminal stations share the common signal line 30 in a time-division manner. Figure 2b
is a signal configuration example of the common signal line 30, the horizontal axis is time, 40 is a reference burst, 41, 42, 43
is a data burst. Data bursts are dedicated to each end station.

Now, in FIG. 1, a terminal station (referred to as a control station) to which lines are collectively allocated is, for example, terminal station 7, and line allocation control will be explained by taking a call from terminal station 5 to terminal station 6 as an example. The terminal station 5 uses the dedicated data burst of the terminal station 5 to request the control station 7 to allocate a line. The control station 7 grasps the line usage status, and if there is an idle line, it notifies the terminal station 5 of the idle line number and manages the line number as being in use. If no free line is found, the terminal station 5 is notified of this fact. When a line is assigned, the terminal station 5 transmits data such as the line number and the destination station in a burst dedicated to the terminal station 5 to each terminal station via the satellite 1. Each terminal station constantly monitors the common signal line 30, and as a result, terminal station 6 detects an incoming call from terminal station 5, learns the line number to be used, and connects terminal stations 5 and 6. A line is set up between them. When the call ends, the terminal station 5 notifies the control station 7 of the release of the line, and as a result, the control station 7 makes the line vacant and prepares for the next call.

FIG. 3 shows an embodiment of the present invention, showing a line allocation control section in the control station 7 of FIG. In FIG. 3, 50 is a memory for storing the number of lines used by each terminal station, 51 is a memory for storing the number of reserved suspensions corresponding to each terminal station, 52 is a register indicating the number of idle lines, and 53 is a reserved line. Register indicating number of lines, 54,5
5 is a comparison circuit, 56 is a CR circuit, 57 is an output of 56, 58 is an address line for memories 50 and 51, 59
is a specific address of the memory 50, 60 is a specific address of the memory 51, 61 is the output of the comparison circuit 55, 62 is the output of the comparison circuit 54, 63 is the input of the register 52, 6
4 is an input of the register 53, 65 is a data bus of the memory 50, and 66 is a data bus of the memory 51. Note that the register 52 is constantly updated with the number of free lines via the input 63, and the memory 50 is updated with the number of used lines via the data bus 65.

The operation of FIG. 3 will now be described using, as an example, a case where a line allocation request is made from the terminal station 5 of FIG. 1.
When the terminal station 5 requests a line, the address line 58
An address corresponding to the terminal station 5 is set, and, for example, the contents of address 59 of the memory 50 and address 60 of the memory 51 corresponding to the terminal station 5 are read out. Address 59 of the memory 50 stores the number of lines currently used by the terminal station 5, address 60 of the memory 51 stores the number of reserved suspensions of the terminal station 5; The contents of addresses 59 and 60 are compared by the comparison circuit 55, and the contents of 59 (number of lines used) < 60
(number of reserved stops), the output 61 of the comparator circuit 55 becomes logic "1". That is, output 61
When is logic "1", it indicates that the terminal station 5 is not using the line up to the number of reserved stops, and therefore line allocation is permitted. At the same time, the contents of the register 52 indicating the number of free lines and the register 53 indicating the number of reserved lines are compared in the comparison circuit 54, and when the content of 52 (number of free lines)>the content of 53 (number of reserved lines),
The output 62 of the comparison circuit 54 becomes logic "1". That is, the fact that the output 62 is logic "1" indicates that the number of free lines is greater than the number of reserved lines, so line allocation is freely permitted. Output 61, 62
is input to the OR circuit 56. This OR circuit 56
When the output 57 is logic "1", line allocation is permitted in response to a line request from the terminal station 5, and when it is logic "0", line allocation is not permitted and the line is not sent to the terminal station 5. You will be notified of the blockage.

To summarize the above, line allocation is permitted when the number of lines used by the terminal station 5 is smaller than the number of reserved and stopped lines, or when the number of idle lines is greater than the number of reserved lines even if it is larger. However, even if the output 57 becomes logic "1" and assignment is permitted, no line will be assigned if there is no free line. Therefore, when the call volume of terminal station 5 increases and the number of lines in use is equal to or greater than the number of reserved and suspended lines, allocation is permitted only when the number of free lines is greater than the number of reserved lines, so only terminal station 5 is subject to unreasonable conditions. The terminal station does not occupy the line or unduly pressure the line requests of other terminal stations. Conversely, if the number of calls from other terminal stations increases, it becomes difficult for terminal station 5 to seize lines, but if the number of lines in use is less than the number of reserved and suspended lines, terminal station 5 is permitted to allocate lines regardless of the number of free lines. Therefore, the line request of the terminal station 5 is not unduly pressured. In this way, even if the number of calls to a particular terminal station increases, the line requests of other terminal stations will not be significantly interfered with.
Uniformity of service can be maintained.

Normally, the number of reserved suspensions stored in the memory 51 can be set by the number of lines used in the design load of each terminal station. Further, the greater the number of reserved lines stored in the register 53, the more uniform the service will be, but since the efficiency of the lines will deteriorate, it is desirable to keep the number to the minimum necessary. It depends on the number of terminal stations and lines, but usually (number of terminal stations) x (1
~2 lines) is sufficient. Note that the number of reserved suspensions and the number of reserved lines can be rewritten depending on traffic conditions and the like.

In the above description, line allocation is controlled for outgoing calls for each terminal station, but it is also possible to control line allocation for incoming calls for each terminal station using a similar method. For example, calls may be concentrated on the terminal station 6 from each terminal station, and a large number of lines are allocated between each terminal station and the terminal station 6, making it difficult to allocate lines between other terminal stations. On the other hand, in the above explanation, the number of lines used for each originating station is managed by the memory 50, but if the number of lines used for each terminal station is managed by the memory 50, the same effect as explained above can be obtained. It will be done. Furthermore, it is also possible to manage the number of lines in use between terminal stations, which prevents traffic between specific terminal stations from increasing and lines between specific terminal stations being occupied and service deterioration between other terminal stations. . In this case, memory 5
0. The memory 51 requires a capacity equivalent to the matrix between terminal stations. For more control,
It is only necessary to manage the number of lines in use for each originating station, each terminating station, and between each terminal station, and for each, the number of reserved outages,
All you have to do is set the number of reserved lines.

Further, in the above explanation, the centralized control method in the variable allocation method was taken as an example, but the present method can also be applied to a distributed control method. In the distributed control system, each terminal station monitors the common signal line 30 shown in FIG. 2 to manage idle lines. Therefore, each terminal station can grasp all the progress of calls between each terminal station, and each terminal station can obtain the information necessary for the function shown in FIG. 3 described above. For example, in a system in which each terminal station is managed, the memory 50 is replaced with a register corresponding to a specific address 59, etc., and the memory 51 is replaced with a register corresponding to a specific address 60, etc. in each terminal station, as shown in FIG. It is sufficient to provide a line allocation control unit shown in FIG. 3, and in a system in which management is performed for each terminal station or a system in which management is performed between terminal stations, the line allocation control unit shown in FIG. 3 may be provided. By controlling the line allocation of the own terminal station according to the output 57, the same effect as described above can be obtained.

As explained above, according to the present invention, in a circuit-switched network using a variable allocation satellite line,
Because line allocation is permitted only when the number of satellite lines in use is smaller than a predetermined value (number of reserved outages) or the number of vacant satellite lines is greater than a predetermined value (number of reserved lines), Even if the number of terminal stations increases, satellite lines will not be over-allocated to a specific terminal station, etc., and reserved satellite lines will be preferentially allocated to other terminal stations, so that the satellite lines from specific terminal stations, etc. This will protect you from pressure and ensure uniformity of service. Additionally, when the number of available lines is greater than the number of reserved lines, satellite lines are allowed to be allocated even if the number of used lines is greater than a predetermined value, so it is possible to use satellite lines effectively. . Note that the present invention can be applied to various circuit switching networks such as facsimile networks and data switching networks in addition to telephone networks.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a telephone network using a variable allocation satellite line, Figure 2a is a diagram showing an example of frequency allocation in the FDM multiple access system, and Figure 2b is an example of the signal configuration of a common signal line. FIG. 3 is a configuration diagram of an embodiment of the present invention. 1...Satellite, 2,3,4...Satellite line, 5,6,7
...terminal office, 8,9,10...exchange, 30...common signal line, 31,32,33...voice line, 40...reference burst, 41,42,43...data burst, 50,51...memory, 52, 53...Register, 54, 55...Comparison circuit, 56...OR circuit, 5
7... Output, 58... Address line, 59, 60... Specific address, 61, 62... Output, 63, 64... Input, 6
5, 66...Data bus.

Claims (1)

[Claims] 1. In a line switching network using variable allocation satellite lines, the maximum number of lines in use (hereinafter referred to as the number of reserved suspensions) for each terminal station, and the maximum number of lines that can be used for each terminal station, and The minimum number of free lines that should be reserved for use at the station (hereinafter referred to as the number of reserved lines) is set in advance, and when a satellite line is requested, the number of satellite lines used by the terminal station related to the request is set in advance. A satellite line allocation control method characterized in that a satellite line is allocated in response to the request only when the number of idle satellite lines is smaller than the number of reserved outages or the number of vacant satellite lines is larger than the number of reserved lines.