JPS6322651B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a satellite line with variable allocation system.
The present invention relates to a line allocation control method for preventing traffic pressure on other terminal stations and service degradation that occurs when traffic at a particular terminal station increases.

In circuit-switched networks such as telephone networks that use satellite lines, there are two methods for allocating satellite lines between terminal stations on the ground: a fixed allocation method that allocates lines in a fixed manner, and a variable allocation method that allocates lines according to the occurrence of calls. However, a variable allocation method is generally used due to line efficiency and 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 is 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 connection 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. In this way, while the variable allocation method is flexible in response to traffic fluctuations,
The drawback is that extreme traffic fluctuations can result in significant unevenness of service.

In order to solve the conventional drawbacks of the above-mentioned variable allocation method, the present invention allocates satellite lines only when the number of satellite lines used between each terminal station and between each terminal station is less than a predetermined value (use limit number). The drawings will be described in detail below.

FIG. 1 is an example of a telephone network using a variable allocation satellite line, where 1 is a satellite, 2, 3, 4 are satellite lines, 5, 6, 7 are terminal stations on the ground, 8, 9, 10 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 following description will take the centralized control method 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 that relays and transmits 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. FIG. 2b shows an example of the signal configuration of the common signal line 30, where the horizontal axis is time, 40 is a reference burst, 41, 42, 4
3 is a data burst. Data bursts are dedicated to each end station.

In FIG. 1, the terminal station (referred to as a control station) that allocates lines all at once is, for example, terminal station 7, and an overview of line allocation in the centralized control method 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 keeps track of the usage status of all lines, and if no free line is found, it notifies the terminal station 5 to that effect. If an idle line is found, the idle line number is notified to the terminal station 5, and the line number is managed as being in use. The terminal station 5 puts data such as the line number and the destination station on a data burst dedicated to the terminal station 5, and sends it to each terminal station via the satellite 1. Each terminal station constantly monitors the common signal line 30, and as a result, the terminal station 6 detects an incoming call from the terminal station 5. At the same time, terminal station 6 learns the line number to be used, and a line is established between terminal stations 5 and 6. When the call ends, the terminal station 5 notifies the control station 7 of the release of the line, which causes the control station 7 to make the line vacant and prepare 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 and the limited number of lines for each terminal station, and 51 and 52 are memories 50.
In the fields for each word in , 51 is a field for storing the number of lines to be used, and 52 is a field for storing the number of usage limits. Reference numeral 53 indicates a register into which a word read from memory 50 is set, and 54 and 55 indicate fields of register 53. 56 is a comparison circuit, 57 is an AND
circuit, 58 is an information line indicating the presence or absence of an idle line, 59
is the output of the AND circuit 57, 60 is the output of the comparison circuit 56, 61 is an address line of the memory 50, 62 is a specific address of the memory 50, and 63 is an adder circuit.

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. Now, when there is a line request from the terminal station 5, an address corresponding to the terminal station 5 is set on the address line 61. For example, if the address of the memory 50 corresponding to the terminal station 5 is set to a specific address 62, the contents of the specific address 62 are read to the register 53, and the number of lines to be used is set in the field 54, and the limit number of lines to be used is set in the field 55. . This field 54 and field 55
The contents of are compared in the comparison circuit 56, and when the number of lines in use is smaller than the limit number of use, that is, when the contents of the field 54<the contents of the field 55, the output 60 of the comparison circuit 56 becomes logic "1". Become. A logic "1" at output 60 indicates that line selection is permitted. This output 60 is ANDed by an AND circuit 57 with an information line 58 indicating whether or not there is an idle line for the corresponding satellite line (it becomes logic "1" when there is an idle line). The output 59 of the AND circuit 57 is logic “1”
When , a line is assigned. When a line is assigned, the content of field 54 is changed to 1 by adding circuit 63.
The contents of the register 53 are added to the specific address 6.
2, and the number of lines in use is updated.

As described above, allocation of lines to the terminal station 5 is permitted only when the number of lines used by the terminal station 5 is smaller than the usage limit number. Therefore, even if the traffic of the terminal station 5 increases, the number of lines in use will not exceed the usage limit, so the terminal station 5 will not occupy the line unfairly, and the lines of other terminal stations will not be occupied. Don't be too demanding in your demands. In this way, when the traffic of a particular terminal station increases, the number of lines in use is limited, which prevents pressure on other calls and prevents uneven service.

Incidentally, when the usage limit number is increased, the pressure on other calls increases, and when it is decreased, on the other hand, the pressure on other calls is suppressed. However, if the number of usage limits is too small, lines will not be allocated even if the line is quite empty and there is no pressure on other calls, impairing the flexible line operation that is a feature of line sharing. Therefore, it is necessary to set the value according to the system. As a rough guideline for telephone networks, lines should be allocated proportionately based on the designed traffic of the terminal stations, and a 20 to 30% increase should be set as the usage limit for each line. Therefore, the total number of usage restrictions is naturally greater than the total number of lines. Further, the usage limit number does not need to be fixed, and it is also possible to change the usage limit number in real time under special traffic conditions.

In the above explanation, line allocation was controlled for outgoing calls for each terminal station, but the same method can be used for various other control methods, such as controlling line allocation for incoming calls for each terminal station. can do.
For example, calls may be concentrated from each terminal station to the terminal station 6, 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 in use for each originating station is managed by the memory 50, but if the number of lines in use for each terminating station is managed by the memory 50, the same effect as in the above explanation 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 degradation between other terminal stations. It becomes possible. In this case, the memory 50 requires a capacity equivalent to the matrix between terminal stations. For more detailed management, the number of lines in use may be managed for each originating station, each terminating station, and between each terminal station, and a usage limit may be set for each.

Further, in the above description, the centralized control method in the variable allocation method was exemplified, but the present invention 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. 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 method of managing each originating station, the memory 50 is replaced with a register corresponding to a specific address 62 (for example, register 53
In the method of managing each terminal station from one's own station, each address in the memory 50 is made to correspond to each terminal station,
The line allocation control section shown in FIG. 3 may be provided. In the method of managing each terminal station, in addition to calls from the own station,
Calls from other stations to the destination station may also be monitored and controlled. By controlling the line allocation of its own terminal station in accordance with the output 59 at each terminal station, the same effect as described above can be obtained.

As explained above, according to the present invention, in a circuit-switched network using variable allocation satellite lines,
A predetermined value for the number of lines used (limited number of usage)
As the allocation of satellite lines is permitted only when the number of calls is smaller than It is possible to protect specific terminal stations from pressure, and uniformity of services can be achieved. Furthermore, by setting the number of lines in use to be larger than the value at the time of the designed load, flexible line operation, which is a feature of line sharing, is not impaired. It should be noted that the present invention is applicable not only to telephone networks but also to various circuit switching networks such as facsimile networks and data switching 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, 8, 9, 10... Exchange, 30
...Common signal line, 31, 32, 33...Voice line, 40...Reference burst, 41, 42, 43
...Data burst, 50...Memory, 51,5
2...Field, 53...Register, 54,5
5...Field, 56...Comparison circuit, 57...
AND circuit, 58...information line, 59, 60...output, 61...address line, 62...specific address, 6
3...Addition circuit.

Claims (1)

[Claims] 1. In a circuit-switched network using variable allocation satellite lines, when a satellite line is requested, the number of used satellite lines related to the request is compared to see if it is smaller than a predetermined number of lines, and if it is smaller than the predetermined number, 1. A satellite line allocation control method, characterized in that a satellite line is allocated to the request as long as possible.