JPH0436618B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for detecting congestion by terminal group, and in particular detects congestion of individual subscriber terminals by counting overflow calls that occur during busy periods of registered terminal groups. This is related to the method of doing so.

[Background of the invention]

Conventionally, individual subscriber congestion has been detected by sequentially registering the terminal number of the overflow call in a memory area of a predetermined size each time an overflow call occurs, and then scanning the memory area at regular intervals. In this method, the number of registered terminals with the same terminal number is counted, and when the count value is equal to or higher than a separately determined threshold, congestion is determined. Furthermore, when the memory area is full, the terminal numbers registered in the memory area are deleted in order from the oldest, and the terminal numbers of newly generated overflow calls are registered. In such a method, in order to make a fair congestion judgment for subscribers, for example, for subscribers who can connect multiple terminals with one terminal number as in the case of a representative service, Congestion can be determined by setting a threshold according to the number of lines owned by the subscriber, or by normalizing the number of registrations in the memory area by the number of lines owned by the subscriber. Although there is a method, there are problems such as increasing memory capacity and complicating processing such as threshold determination and congestion determination.

In addition, since the terminal number registered in the memory area is searched at a certain period,
For example, if a large number of overflow calls occur concentratedly on a certain terminal number, the memory area for registration becomes full due to the large number of overflow calls to that terminal, and the terminal numbers of other congested subscribers are deleted. , there is a problem that it is overlooked.

Furthermore, since congestion detection can only be performed at fixed time intervals, if the terminal number search cycle is long, there will be a long period of time between the actual occurrence of congestion and congestion processing, and the congestion state during that time cannot be relieved. Conversely, if the search period is shortened in order to prevent this, the processing of the congestion detection device for searching increases.

[Purpose of the invention]

The purpose of the present invention is to solve such conventional problems, to judge congestion using a reference value that does not depend on the number of lines owned by a subscriber, and to improve the reliability of congestion judgment.
Another object of the present invention is to provide a congestion detection method for each terminal group that can immediately respond to the occurrence of a congestion state.

[Summary of the invention]

In order to achieve the above object, the terminal group-specific congestion detection method of the present invention includes (a) storage means for a connection line counter indicating the number of free terminals in a registered terminal group, and an overflow call counter indicating the number of overflow calls in a registered terminal group; and a congestion detection means for reading/writing to and from both storage means and detecting congestion of the registered terminal group, and the congestion detection means receives a connection request from the exchange to the registered terminal group.
The connection line counter is read to determine whether the registered terminal group is idle or blocked. If all of the registered terminals are blocked, 1 is added to the overflow call counter, and if there is a vacancy, the connection line counter is subtracted by 1. When a disconnection signal from a terminal in a terminal group that is currently on a call is received, 1 is added to the connected line counter, the overflow call counter is compared with a predetermined threshold, and if the counter value of the overflow call counter is less than the threshold, the current If it is in a congested state, the congested state is canceled, and if the counter value is greater than or equal to a threshold value, it is determined that the registered terminal is in a congested state, and the detection device memorizes that the registered terminal is in a congested state,
The exchange notifies the originating terminal at a specific rate or a specific absolute number that it is congested using announcements, messages, or busy tones, performs congestion processing to limit originating requests, and then changes the counter value of the overflow call counter. It is characterized by correction. (b) When the congestion detection means receives a connection request from the exchange to the registered terminal group, it reads the connection line counter to determine whether the registered terminal group is idle, and if all the registered terminals are occupied, the overflow call counter is read. If there is a free space, add 1 to the corresponding connection line counter.
The overflow call counter is compared with a predetermined threshold, and if the counter value of the overflow call counter is less than the threshold and the registered terminal is currently congested, the congestion state is canceled and the counter value is equal to or higher than the threshold. If so, it is determined that the registered terminal is in a congested state, and the detection device memorizes that the registered terminal is in a congested state, and sends an announcement, message, or busy tone from the exchange to the originating terminal at a specific rate or in a specific absolute number. It notifies that there is congestion, performs congestion processing to limit call requests, and when a disconnection signal from a terminal that is currently talking among the registered terminals is received from the exchange, 1 is added to the connected line counter.
Another feature is that the counter value of the overflow call counter is corrected after that.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a telephone network showing one embodiment of the present invention.

In FIG. 1, 1 is a general subscriber terminal (general terminal), 2 is a group of registered terminals having one or more lines for one terminal number, 3, 4
1 is a subscriber exchange, 5 and 6 are telephone lines, 7 is a trunk exchange, 8 is a transmission line, 9 is a congestion detection control device, 1
0 is a memory, 11 is a connection line counter for managing the number of connectable lines for each terminal number, and counts the number of simultaneous connections of a group of terminals, and 12 is an overflow call counter for counting overflow calls for each terminal number. It is a counter.

The terminal number of the registered terminal group 2 and terminal information such as the number of terminals and the number of lines are registered in the trunk switch 7 and the congestion detection control device 9, respectively. The congestion detection control device 9 stores the number of lines of the terminal group in accordance with the terminal number of the registered terminal group 2, and also reads and writes the connected line counter 11 and the overflow call counter 12 which have areas in the memory 10. . It also notifies the trunk switch 7 of the blockage status of the registered terminal group 2 and the like.

FIG. 2 is a flowchart showing the operation of one embodiment of the present invention.

Now, when the terminal number of the registered terminal group 2 is dialed from the general terminal 1, the general terminal 1 is connected to the trunk exchange 7 via the subscriber line exchange 3 and the telephone line 5 in a conventional manner. (step
101). When the trunk switch 7 that has received the terminal number identifies that it is the number of the registered terminal group 2 (step 102), it sends the received terminal number to the congestion detection control device 9 through the transmission line 8. 2
After notifying that a 'call' connection request has occurred to the terminal number of (step 103), the congestion detection control device 9
The call is connected to the subscriber line exchange 4 and the registered terminal group 2 in accordance with the blocked state (step 104).

The congestion detection control device 9 uses the connection request notification, that is, the received terminal number of the registered terminal group 2 (step 201), to read the connection line counter 11 indicating the number of free terminals in the registered terminal group 2. As a result (step 202), there are unconnected (empty) terminals.
Connection of the call is possible (connection line counter value ≠
0), 1 is subtracted from the value of the connection line counter 11 of the registered terminal group 2 (step 203,
205), when there are no unconnected (vacant) terminals (connection line counter value = 0), that is, all terminals in registered terminal group 2 are busy, and it is impossible to connect a 'call', registered terminal group 2 The value of overflow call counter 12 is 1.
is added and the overflow call counter is updated (step
204).

Thereafter, when any receiving terminal in the registered terminal group 2 disconnects (ends the call), the trunk switch 7 that formed the communication path for that call detects the disconnection signal (step 106), and the terminal is registered. (Step 107), similarly to when a 'call' is connected, it notifies the congestion detection control device 9 through the transmission path 8 that the terminal in the registered terminal group 2 has disconnected (ended the call). (Step 108).

When the congestion detection control device 9 receives a disconnection signal that is a call termination notification (step 207), the congestion detection control device 9 uses the terminal number of the registered terminal group 2 to check the connection line counter 11 indicating the number of free terminals in the registered terminal group 2. After adding 1 to the value of (step 208), the value of the overflow call counter 12 corresponding to the registered terminal group 2 is compared with a preset constant threshold (step 209). When the result exceeds the threshold, the registered terminal group 2 determines that there is congestion, and in order to alleviate the congestion, the congestion detection control device 9 notifies the relay exchange 7 that it is in a congested state. performs congestion processing such as message creation. The relay exchange 7 notifies the originating terminals of congestion by an announcement, message, or busy tone at a specific rate or in a specific absolute number, and limits originating requests. Through such operations, incoming calls to the subscriber exchange during congestion are restricted to alleviate congestion (steps 210, 211). If the congestion detection control device 9
In a state where the congestion state has already been detected, the overflow call counter 12 is compared with the threshold value, and the overflow call counter 12 is detected.
If the value of does not exceed the threshold, the congestion detection control device 9 determines that the congestion state of the registered terminal 2 has been released, executes congestion release processing such as resetting the congestion flag, and also resets the congestion state of the transit exchange 7. We will notify you of the cancellation. The trunk exchange 7 then performs normal incoming call connection operations (step 212,
213).

After executing the above processing, the overflow call counter 12
Post-processing is performed (step 214). This post-processing is
The counter value of the overflow call counter 12 is also corrected, and there are the following two methods.

(a) The value of the overflow call counter 12 used for comparison in step 209 is cleared to 0. Therefore, when the next overflow call occurs, the overflow call counter 12 is incremented by 1, so that the counter value becomes 1.

(b) Set a correction value based on the counter value of the overflow call counter 12 used for comparison in step 209. Therefore, when the next overflow call occurs, the overflow call counter 12 is incremented by 1, so that the counter value becomes (correction value + 1). The correction value is obtained by a predetermined functional formula based on the past several counter values at the time of comparison with the threshold value (at the time of step 209). For example, if the counter value of the overflow call counter 12 at step 209 is X _o-1 , the counter value is reduced by (1/2) at step 214.
Compare the value of X _o-1 +X with the threshold value. Here, X
is the number of overflow calls that occurred between the correction of the counter value in step 214 and the comparison with the next threshold value (step 209), and X _o is the counter value of the overflow call counter 12 at the nth comparison. (n=1,
2,…).

In the present invention, since congestion is detected and cleared at the end of a call at any terminal (terminal disconnection), the time interval from one disconnection to the next disconnection varies depending on the time and call. Therefore, the number of overflow calls measured at each disconnection interval also varies. In method (a), if there is a large variation in the number of overflow calls, the threshold value must be increased to absorb the variation, which makes it impossible to accurately determine the congestion state. On the other hand, if the threshold value is set to a small value, it will be easy to mistakenly judge that congestion is occurring, and the exchange will send announcements, messages, or busy tones to the calling terminal at a certain rate or in a certain absolute number, even though they are not necessary. Congestion processing will occur frequently to notify that this is the case and limit outgoing requests.

Further, in the method (b), the initial value of the overflow call counter 12 changes depending on the previous counter value.
That is, by correcting the number of overflow calls for detecting congestion from the history of past overflow calls, congestion can be detected in accordance with the overflow state of calls.

For example, the correction value is always 1/1 of the previous count value.
2, so if the number of overflow calls is increasing, the value of 1/2 of the previous counter value will also increase,
As a result, the number of overflow calls to detect congestion,
In other words, from the threshold value to the correction value (1/ of the previous count value)
2) becomes smaller, and if it is in a decreasing trend, the value of 1/2 of the previous counter value will also decrease, and as a result, the number of overflow calls (threshold value) for detecting congestion will decrease. (value minus the correction value) becomes larger. In other words, the larger the number of overflow calls that occur, the more likely it is to be in a state where it is determined to be congestion, and the smaller the number of overflow calls, the less likely it is to be in a state where it is determined to be congestion.

Note that the calculation formula for the correction value shown in the explanation of method (b) above is a calculation formula when only the previous counter value is used, and the coefficient of (1/2) is based on the result of the simulation. This is an example of what was done. Various calculation formulas can be used for this calculation formula depending on how many past counter values are used.

FIG. 3 is a flowchart showing the operation of another embodiment of the present invention.

In the above-mentioned embodiment, as shown in FIG. 2, after receiving the call termination notification of the registered terminal group 2 from the relay exchange 7, the overflow call counter 12 is compared with the threshold value (reference value) to determine the congestion and determine the overflow call. Although the counter 12 is post-processed, in another embodiment, as shown in FIG. 3, after receiving a connection request notification from the relay exchange 7 to the registered terminal group 2, an overflow call is made in the same way as in FIG. Congestion is determined by comparing the threshold value (reference value) of the counter 12. The difference between the above two is that in Fig. 3, when registered terminal group 2 is busy, the congestion situation is determined every time a 'call' connection is requested, whereas in Fig. 2, registered terminal group 2 This method determines the same congestion situation when a call is busy and any terminal disconnects, that is, the call ends.

Note that in the embodiments described so far, the threshold value in step 209 for determining a state of congestion and the threshold value for releasing a state of congestion have been set to the same value, but it is also possible to select independent values for each. . Comparison and determination between the threshold value to be released at that time and the overflow call counter 12 can be performed after step 212.

The trunk switch 7 performs connection requests to the congestion detection control device 9, notification of call termination, and call disconnection detection, but by connecting the transmission line 8 to the subscriber switch, the above functions It is also possible to use a line exchange.

In steps 202 and 203, the value of the connection line counter 11 was used to determine whether the registered terminal group 2 was blocked.
This can also be done by directly monitoring the subscriber line, or the congestion detection control device 9 can make an inquiry to the subscriber line exchange 4 using a new transmission path.

Rather than providing the congestion detection control device 9 and the memory 10 independently as shown in FIG.
It is also possible to install it in conjunction with the trunk line exchange 7, the subscriber line exchanges 3 and 4, or any other exchange not shown in FIG. 1 for economical purposes.

In this way, in a telephone network such as that shown in FIG. A counter 12 is provided, and the contents of the two counters are referred to when connecting and disconnecting from a registered terminal group to detect congestion and perform congestion release processing. The number of disconnections within a unit time increases, and the measurement interval for the number of overflow calls becomes shorter. On the other hand, if the number of owned lines is small, the time required to measure the number of overflow calls will be longer, so if the frequency of calls on each line is about the same, the total number of overflow calls measured during the measurement period will be equal to the number of overflow calls. It is a value that does not depend on the number of lines, and a fixed threshold value that is independent of the number of lines owned by the registered terminal group can be used to determine congestion. Furthermore, since the connection and disconnection of a call are used as congestion detection timings, congestion processing can be performed in response to actual congestion conditions, compared to conventional methods that detect congestion at regular intervals. Furthermore, since the counter value of the overflow call counter 12 is corrected based on the previous overflow call counter value, congestion can be determined according to the state of occurrence of overflow calls.

〔Effect of the invention〕

As explained above, according to the present invention, the overflow call counter for determining the congestion of the registered terminal group is updated and corrected at the time of the connection request to the registered terminal group and the end of the call, so it depends on the number of owned lines. Congestion can be determined based on a certain reference value that does not occur, and the memory capacity for the counter does not need to be increased. Further, by making a congestion judgment according to the occurrence state of an overflow call, the reliability of the congestion judgment can be improved, and furthermore, it is possible to perform congestion processing that immediately responds to the occurrence of an actual congestion state.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a telephone network showing an embodiment of the present invention, and FIGS. 2 and 3 are flowcharts showing the operation of the embodiment. 1: General subscriber terminal (general terminal), 2: Registered terminal group, 3, 4: Subscriber line exchange, 5, 6: Telephone line, 7: Trunk line exchange, 8: Transmission line, 9: Congestion detection control Device, 10: Memory, 11: Connection line counter, 12: Overflow call counter.

Claims (1)

[Scope of Claims] 1. In a terminal group-specific congestion detection method for detecting the congestion state of a registered terminal group in a telephone network having a registered terminal group and an exchange, storage of a connection line counter indicating the number of empty terminals in the registered terminal group. means for storing an overflow call counter indicating the number of overflow calls of the registered terminal group; and congestion detection means for calling/writing to both storage means and detecting congestion of the registered terminal group; , upon receiving a connection request from the exchange to the registered terminal group, reads the connection line counter to determine whether the registered terminal group is idle, and if all are blocked, adds 1 to the overflow call counter;
If there is a free space, the connected line counter is decremented by 1, and when a disconnection signal from a terminal that is currently talking among the registered terminals is received from the exchange, 1 is added to the connected line counter, and the overflow call counter is and a predetermined threshold, and if the counter value of the overflow call counter is less than the threshold and congestion processing is currently in progress, the congestion state is canceled, and if the counter value is equal to or greater than the threshold, congestion processing is performed; The congestion detection method by terminal group is characterized in that the counter value of the overflow call counter is then corrected. 2. In a terminal group-based congestion detection method for detecting the congestion state of a registered terminal group in a telephone network having a registered terminal group and a switch, storage means for a connection line counter indicating the number of empty terminals in the registered terminal group; storage means for an overflow call counter indicating the number of overflow calls in a group; and congestion detection means for reading/writing to and from the storage means and detecting congestion in the registered terminal group; When a connection request to a terminal group is received, the above-mentioned connection line counter is read to determine whether the registered terminal group is idle or busy. If all of the registered terminals are occupied, 1 is added to the above-mentioned overflow call counter, and if there are vacancies, Set the connection line counter to 1
The overflow call counter is compared with a predetermined threshold, and if the counter value of the overflow call counter is less than the threshold and the registered terminal is currently congested, the congestion state is canceled and the counter value is If it is greater than or equal to the threshold, it is determined that the registered terminal is in a congested state, and the detection device memorizes that the registered terminal is in a congested state;
The exchange notifies the originating terminal at a specific rate or in a specific absolute number that it is congested using announcements, messages, or busy tones, performs congestion processing that limits outgoing requests, and then sends a message from among the registered terminals from the exchange to A congestion detection method for each terminal group, characterized in that when a disconnection signal from a terminal during a call is received, 1 is added to the connected line counter, and then the counter value of the overflow call counter is corrected.