JPS5841022B2 - Bidirectional line selection control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bidirectional line selection control system in a circuit switched network such as a telephone switched network, a data switched network, or a facsimile switched network.

In a circuit-switched network, a bidirectional line that combines outgoing and incoming lines has the advantage of being able to use lines more efficiently than a one-way line that separates outgoing and incoming lines.

However, since the line is used for outgoing and incoming calls at the same time,
If the call volume for either outgoing or incoming calls increases more than the designed call volume, the call may occupy more of the two-way line than the designed value, putting pressure on calls in the other direction, or both outgoing and incoming calls may The drawback is that they compete for the line, resulting in double seizure of the line and lead to invalid switching operations.

In order to eliminate this drawback, there is a method of reserving the line so that it can be captured preferentially for the purpose of protecting outgoing or incoming calls.

According to this method, for example, when lines are reserved for outgoing calls, even if the volume of incoming calls increases, some lines are reserved for outgoing calls, so it is possible to prevent outgoing calls from being overwhelmed.

However, even when the volume of outgoing calls increases, lines are reserved for outgoing calls, so the reservation operates to put more pressure on incoming calls, resulting in an increased pressure on incoming calls.

Since it is generally uncertain whether the outgoing or incoming call volume will increase, this method has the disadvantage that it cannot always be said that the call traffic of the oppressed side is protected.

The present invention has been made to solve the above-mentioned drawbacks, and it sets a predetermined number of line reservations and a predetermined number of reserved suspensions for each line selection direction, monitors the number of lines in use, and Only when the number of bidirectional lines in use is smaller than the number of reserved outages in that arbitrary direction, or when the number of free lines in the two-way line is greater than the number of reserved lines in the other direction, is the line captured in any direction allowed. This provides a bidirectional line selection control system that can effectively protect the other call even if the volume of outgoing or incoming calls increases.

According to an embodiment of the present invention, the number of lines reserved and the number of lines suspended are appropriately changed according to the current state of call volume in both directions, thereby making it possible to more effectively protect the passage of calls. A selection control scheme is provided.

Hereinafter, details of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram for explaining a relay system between two stations in a two-way circuit switching network, where 11 is a two-way circuit;
2 and 13 are exchanges A and B.

FIG. 2 is a conceptual diagram for explaining the present invention in detail based on the block diagram of FIG. 1, where N is the total number of bidirectional lines between exchanges A and B in FIG. transmission (hereinafter simply referred to as "transmission").

), La is the predetermined number of reserved suspensions for outgoing calls, Ra is the predetermined number of reserved lines for outgoing calls, and nb is the number of incoming calls from exchange B to exchange A in Figure 1 (hereinafter It is simply called "incoming call."

), Lb is the predetermined number of reserved lines for incoming calls, Rb is the predetermined number of reserved lines for incoming calls, and X is the number of vacant lines in both directions.

For each of outgoing and incoming calls, the number of hold stops La, Lb
Then, predetermined values of the reserved lines Ra and Rb are assigned, and the numbers na and nb of used lines are monitored.

When the number of lines used for outgoing calls na is smaller than the number of reserved suspensions La (
Ra lines are reserved for outgoing calls, and na〉La
Suspend reservations regarding outgoing calls.

Similarly, when the number of lines used for incoming calls n5 is smaller than the number of reserved suspensions Lb (n5 < Lb), Rb lines are reserved for incoming calls,
When nb>Lb, suspension of incoming calls is stopped.

Here, the meaning of holding Ra lines on hold will be explained using a call as an example.

Reserving Ra lines for outgoing calls means that the number of free lines
When <, Ra, only outgoing calls are allowed to capture the free line, and incoming line capture is prohibited; when X>Ra, the outgoing line is allowed to capture
This is to reserve books and allow the remaining free lines to be used for incoming calls as well.

As described above, one of the features of the present invention is that reservation is performed when the number of lines in use is less than or equal to the number of lines in use, and that reservation is stopped when the number of lines in use is greater than or equal to the number of lines in use.

The present invention will be described in detail below, taking transmission as an example.

FIG. 2a shows an example of setting La and Lb, and FIG. 2a shows a state where the number of incoming calls increases and na is less than La.

Since na<La, Ra lines are reserved for outgoing calls.

When X > Ra, the line can be captured for incoming calls, but when X > Ra
When this happens, line capture for incoming calls is prohibited, and free lines are reserved for outgoing calls only.

Therefore, even if the number of incoming calls increases, outgoing calls are protected from the pressure of incoming calls.

Figure 2C explains the case where the number of calls increases and na≧La.Since n1≧La, the reservation of calls is stopped and it is no longer possible to unconditionally capture vacant lines. , examines the relationship between X and Rb and seizes the line.

When X > Rb, the outgoing caller can seize a free line, but when X > Rb, the free line is reserved for incoming calls only, so even if there is a free line, outgoing calls are prohibited from seizing the line, which puts pressure on incoming calls. There isn't.

Therefore, according to the present invention, even if the number of outgoing or incoming calls increases, the other one can be protected.

From the above explanation, the conditions under which a caller is allowed to seize the line are na
<La or X>Rb, and it is sufficient to check this condition when acquiring the line.

Note that this condition is a permissive condition for line capture, so for example, even if line capture is permitted based on na<La, in reality X=
Of course, if it is 0, line acquisition will not be achieved.

Next, the number of reserved lines Ra, Rb, and the number of reserved lines La.

The value of Lb will be explained.

Ra, Rb, La, and Lb do not impose restrictions on their respective values as long as they satisfy 0ζLaζN, 0*Lb*N, 0*Ra*La, and 0*Rb*Lb.

The larger Ra and La are, the stronger the protection for transmission becomes;
The larger the Lb, the stronger the protection for incoming calls.

Specific examples of Ra, Rb, La, and Lb include Ra, Rb
A suitable example is one to several lines, La/Lb=normal outgoing call volume/normal incoming call volume, and La+Lb=N, but is not limited to this.

For example, regarding La and Lb, although La+Lb=N was explained as an example in Fig. 2a, it is also possible to set La+Lb>N (Fig. 2b), and in this case, the overlapping part of La and Lb is the line capture for both outgoing and incoming calls. Therefore, in fact, La=N−Lb
, Lb=N-La, which is equivalent to the case of La+Lb<H (FIG. 2e) on the - plane.

However, if La and Lb are set as shown in Figure 2 e, Min
Since the (Ra, Rb) line will no longer be used, it is more desirable to set it up as shown in the equivalent figure 2d.

Regarding Ra and Rb, at least the Ra line can be used only for outgoing calls, and at least the Rb line can be used only for incoming calls, so as a special usage example, the second
Ra = La, Rb = Lb as shown in figure f
.

If Ra + Rb = N, this is equivalent to assigning an La line exclusively for outgoing calls and an Lb line exclusively for receiving calls (converting a two-way line to a one-way line), completely preventing pressure from the other direction. You can also.

Also, for example, for the purpose of prioritizing incoming calls, La = 0,
It is also possible to set Ra = 0 and Lb = N.

Further, by setting La=Lb=N and Ra=Rb=0, it is also possible to select a normal bidirectional line.

As described above, the call volume of outgoing and incoming calls can be controlled for various purposes by combining Ra, Rb, La, and Lb.

According to one embodiment of the invention, Ra. Since the values of Rb, La, and Lb can be changed, for example, usually La+Lb=N, La
/Lb=normal outgoing call volume/normal incoming call volume, Ra, Rb=1
~ Set up several lines, for example, when the volume of incoming calls increases extremely, La = O, Ra = for the purpose of giving priority to incoming calls that have undergone more switching processing within the network from the viewpoint of network adhesion. O
, it is possible to change the setting to Lb=N, or to change the setting to Ra=La, Rb=Lb, or Ra+Rb=N to make a two-way line into a one-way line for the purpose of ensuring that the call goes through. It also has the feature of being able to selectively control bidirectional lines over a wide range of areas.

FIG. 3 is a functional block diagram for explaining an example of the hardware configuration of the present invention, taking the A side of FIG. 1 as an example.

31 is a register indicating n3, 32 is a register for accumulating La, 33 is a register for X, 34 is a register for accumulating Rb, 35 and 36 are comparators, 37 is an OR logic circuit,
38. is an exchange processing device, and 39 and 40 are control lines.

Contents of register 317.33 n8. X is exchange processing device 3
8 through the control line 39.

The values in the registers 31 and 32 are compared by a comparator 35.

When the value of register 31 is smaller than the value of register 32 (n
a<La) The output of the comparator 35 becomes °°1''.

Therefore, when na<La, the output of the OR logic circuit 37 also becomes logic 41111.

The logic “1” of the OR logic circuit 37 output is the switching processing device 3.
8 is given permission to seize the line.

The values of registers 33 and 34 are compared by a comparator 36.

When the value of register 33 is thicker than the value of register 34 (
X>Rb) The remaining capacity of the comparator 36 becomes logic n191.

Therefore, when X>Rb, the output of the OR logic circuit 37 becomes logic n 1 n, giving permission to the switching processing device 38 to seize the line.

The above-mentioned embodiment realizes the condition n3<La or X>Rh under which the above-mentioned call can seize the line.

As mentioned above, the value La of registers 32 and 34.

Rb can be changed from the exchange processor 38 via the control line 40.

With this function, it is possible to deal with fluctuations in the amount of outgoing and 2nd terminating calls.

For example, when the ratio of incoming and outgoing calls between day and night changes significantly,
It is necessary to change La, Lb, Ra, and Rb accordingly, but in such a case register 32.3
This can be handled by changing the settings of the registers 32 and 34 installed at the A and B stations from their respective exchange processing devices at the A and B stations.

Regarding the setting change, in addition to being able to change the setting to a predetermined value at a predetermined time, it is also possible to measure the traffic volume in both directions with the exchange processing device and change the setting to an arbitrary value at an arbitrary time.

The principle of the present invention and an example of the hardware configuration have been explained above by focusing on the A side of the bidirectional circuit switching network illustrated in FIG.
Since the case focusing on the central office side is exactly the same as that described above, there is no need for a redundant explanation.

Since the present invention has the configuration described in detail above,
Even if the call volume increases in either direction, it will not put pressure on calls in the other direction, and fluctuations in the call volume in one direction will not cause problems in the other direction.

Furthermore, as shown in one embodiment of the present invention, the number of reservations and suspensions can be set and changed, so there is an advantage that selection control of bidirectional lines can be performed over a wide range in response to call volume and network conditions.

[Brief explanation of drawings]

FIG. 1 is a diagram of a relay system between two stations, FIG. 2 is a conceptual diagram explaining the present invention in detail, and FIG. 3 is an embodiment of the hardware configuration of the present invention. 11; Bidirectional line, 12, 13; Exchange, 31°32.
33, 34; Register, N; Number of bidirectional lines, 35.36
; Comparator, La, Lb: Number of reserved stops, 37; OR logic circuit, X: Number of idle lines, 38; Exchange processing device, na
, nb・; Number of lines used, 39, 40; Control line.

Claims (1)

[Claims] 1. In bidirectional circuit selection in a circuit-switched network, set a predetermined number of reserved lines and a predetermined number of reserved suspensions for each line selection direction, monitor the number of bidirectional lines in use, and determine whether the number of bidirectional lines in use in the first direction is the corresponding one. It is characterized in that line acquisition in the first direction is allowed only when the number of reserved lines in the first direction is smaller than the number of lines reserved in the first direction, or only when the number of vacant lines in the two-way line is larger than the number of lines reserved in the second direction. A selective control method for bidirectional lines.