JPS6242549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a call transfer method, in particular a blockage indicator that indicates the blockage status of each accommodated subscriber, to automatically transfer an incoming call to an absent subscriber to a forwarding destination subscriber. In this case, the idle display unit for the absent subscriber is temporarily blocked until a call blocking signal is received or a response signal is received, thereby preventing the incoming call transfer operation from being repeated and continued. Concerning call forwarding method.

FIG. 1 is a diagram illustrating a conventional call transfer method in a local telecommunications exchange. In FIG. 1, subscriber telegraph terminal b (hereinafter referred to as subscriber) accommodated in the subscriber telecommunications exchange and assigned subscriber number nb is absent, so calls incoming to subscriber b are sent to subscriber number nc. performs a predetermined recording operation to transfer the subscriber c to another subscriber c to which the subscriber has been granted the subscriber c. As a result, main memory
In the MM, the call transfer registration indicator T in the subscriber file SFB provided corresponding to subscriber b is set to a logical value of 1, and the subscriber number nc is stored as the transfer destination subscriber number TN. . In such a state, subscriber a makes a call to subscriber b, and the subscriber number nb
When the subscriber number nb is transmitted, the subscriber number receiving unit SSR of the central processing unit CPU receives the subscriber number nb via the communication path network SW consisting of a line termination device and a communication control device, and sends it to the receiving number translation unit PTL. introduce. The received number translation unit PTL identifies whether the received subscriber number nb indicates a subscriber of the local station or a subscriber of another station. In this example, it is determined that the local station subscriber b is indicated, and the subscriber number nb is determined by the local station subscriber translation unit.
Communicate to TLR. The subscriber translation unit TLR of the own station refers to the subscriber file SFB in the main storage device MM corresponding to the received subscriber number nb, and since the call transfer registration indicator T is a logical value 1, it indicates that the call transfer is being registered. It is determined that there is a transfer destination subscriber number extraction unit TNF. The transfer destination subscriber number extraction unit TNF is
Transfer destination subscriber number TN to said subscriber file SFB
Extract the subscriber number nc stored as
The received digits are transmitted to the translation unit PTL. The received number translation unit PTL determines that the received subscriber number nc indicates the local subscriber, and transmits it to the local subscriber translation unit TLR.
Local station subscriber translation unit TLR receives subscriber number nc
Refers to the subscriber file SFC corresponding to , and since the call diversion registration indicator T is a logical value of 0, it is determined that the call diversion is not registered, and the subscriber number nc is transmitted to the called subscriber block processing unit IBD. The incoming subscriber blockage processing unit
The IBD refers to the empty/busy indicator LM in the main memory MM and identifies whether the logical value of the subscriber c corresponding section is 0 or 1. If the logical value is 0, it is determined that the subscriber c is in an idle state, and the logical value is changed to a logical value 1 indicating a blocked state, and the called subscriber activation/calling unit IP is activated. The called subscriber activation/calling unit IP executes activation and calling processing for subscriber c via the communication channel network SW, notifies the reception of the call transfer call,
A communication path p is set up between subscribers a and c, and subscriber a is notified that the call has been transferred to subscriber c. If the incoming subscriber blockage processing unit IBD is the blockage display unit
If a logical value of 1 is identified from LM, it is determined that subscriber c is in a blocked state, and the called subscriber blockage post-processing unit BP
and execute the predetermined post-processing.

In such a conventional call forwarding system, as shown in FIG. When subscriber c also registers call forwarding with subscriber b as the forwarding destination subscriber, the subscriber file SFB corresponding to subscriber b in the main storage device MM of the local telecommunications exchange for station A will contain the same information as shown in Figure 1. ,
A logical value 1 is stored as the call transfer registration indicator T, and the subscriber number nc is stored as the transfer destination subscriber number TN. At the same time, the main memory of the local telephone exchange for station B
Subscriber file corresponding to subscriber c in MM
SFB also has a logical value of 1 as call forwarding registration indication T.
However, the subscriber number nb is stored as the transfer destination subscriber number TN. When subscriber a makes a call to subscriber b in such a state, the central processing unit CPA of the local telephone exchange for station A calls the subscriber in the same process as described above.
The received number translation unit PTL receives the subscriber number nc extracted as the transfer destination subscriber number TN from the subscriber file SFB, determines that the subscriber number nc indicates a subscriber of another station B, and transmits the outgoing route. It is transmitted to the decision unit RS. The outgoing route determining unit RS connects the trunk line TL1 to station B.
is selected, and the subscriber number nc is sent to the trunk line TL1 via the communication network SWA. In the central processing unit CPB of the subscriber telephone exchange for station B, which has received the subscriber number nc from the trunk line TL1, it also receives the transfer destination subscriber number from the subscriber file SFC in the same way as in station A.
The reception number translation unit PTL that receives the subscriber number nb extracted as TN transfers the subscriber number nb to another station A.
, and transmits it to the outgoing route determining unit RS. The outgoing route determining unit RS is a trunk line leading to station A.
Select TL2 and connect trunk line TL via communication network SWB
2 to send the subscriber number nb. Having received the subscriber number nb from the trunk line TL2, the central processing unit CPA of the subscriber telecommunications exchange for station A sends the subscriber number nb to station B again in the same process.
The central processing unit CPB of the subscriber telephone exchange for station B repeatedly selects the trunk line leading to station A, and finally all the trunk lines between stations A and B are occupied. , it may even block communication between the two stations A and B.

As is clear from the above explanation, in the conventional call transfer system, if subscribers b and c of other stations A and B mutually double-register as forwarding destination subscribers, subscriber b or c When a call arrives, the relay line between stations A and B is blocked by the transferred call, and there is a risk that communication between both stations A and B will be blocked. Even when subscribers are mutually registered as forwarding destination subscribers, processes such as management within the same central processing unit (CPU) are adopted, making it difficult to perform flexible call forwarding.

It is an object of the present invention to eliminate the drawbacks of the conventional call transfer method as described above, to allow subscribers of other stations to be selected as transfer destination subscribers, and to prevent blockage of communication between stations due to mutual double registration. The goal is to implement a call forwarding method.

The purpose of this is to provide a switching system that is equipped with a blockage display unit that indicates the blockage status of each accommodated subscriber and a function that automatically transfers an incoming call to an absent subscriber to a forwarding destination subscriber. If the subscriber who requested call forwarding receives an incoming call while the subscriber is absent and the subscriber is absent, the call will be forwarded until the called party block signal is received or a response signal is received. Temporary blockage processing means TIB, TIR for maintaining the blockage display section of the subscriber who requested the call transfer in a blockage display;
This is achieved by providing

An embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a diagram showing a call transfer method according to an embodiment of the present invention. Note that the same reference numerals indicate the same objects throughout the figures. The difference between FIG. 3 and FIGS. 1 and 2 is that the central processing units CPA and CPB are provided with temporary blocking processing means, and this means blocks the subscriber response section of the vacancy display section LM. It consists of an absent subscriber blockage processing unit TIB which displays a blank subscriber, and an absent subscriber blank transition processing unit TIR which cancels the blockage display and displays a vacant subscriber block.

The absent subscriber blockage processing unit TIB is an absent subscriber block transfer processing unit before the transfer destination subscriber number extraction unit TNF.
The TIR is provided after the response processing unit ANS, which detects the idle state of the called party. Similar to FIG. 2, in FIG. 3, subscriber b accommodated in station A,
Subscriber C, who is accommodated in station B, mutually double-registers call forwarding and saves the subscriber file in the main memory MMA.
The SFB stores a logical value 1 as a call transfer registration display T and the subscriber number nc as a transfer destination subscriber number TN, and the subscriber file SFC in the main storage MMB stores a call transfer registration display T as a call transfer registration display T. Logical value 1 and subscriber number nb as forwarding subscriber number TN
is stored. In such a situation, when subscriber a calls subscriber b and sends the subscriber number nb, station A
The central processing unit CPA of the subscriber telecommunications exchange receives the subscriber number nb via the communication channel network SWA, and
In the same process as in the figure, the subscriber number receiving section
It is transmitted to the own subscriber translation unit TLR via the SSR and the received digit translation unit PTL. Local subscriber translation department TLR
refers to the subscriber file SFB corresponding to the received subscriber number nb, identifies that the call transfer registration indicator T is a logical value 1, and sends the absent subscriber block processing unit to the subscriber file SFB corresponding to the received subscriber number nb.
Convey subscriber number nb to TIB. The absent subscriber blockage processing unit TIB is the blockage display unit LM in the main memory MMA.
, it is identified that the subscriber b corresponding section is set to a logical value of 0 indicating an empty state, the logical value is temporarily changed to 1, and the transfer destination subscriber number extraction section TNF is activated. Thereafter, in the same process as described above, the transfer destination subscriber number extraction unit TNF extracts the subscriber number nc, which is the transfer destination subscriber number TN, from the subscriber file SFB and transmits it to the reception digit translation unit PTL.
determines that the subscriber number nc indicates a subscriber of another station B, and uses the outgoing route determination unit RS to connect the trunk line TL to station B.
1 and causes the trunk line TL1 to transmit the subscriber number nc. On the other hand, when the central processing unit CPB of the subscriber telephone exchange for station B receives the subscriber number nc from the trunk line TL1 via the communication network SWB, the central processing unit CPA
In the same process as above, the trunk line TL2 leading to station A is
Select and send the subscriber number nb. Trunk line TL2
The subscriber number nb received by the central processing unit CPA via the communication channel network SWA is passed through the subscriber number receiving unit SSR received digit translation unit PTL and the local subscriber translation unit TLR in the same process as the previous time. and is transmitted to the absent subscriber blockage processing unit TIB. The absent subscriber blockage processing unit TIB that received the subscriber number nb refers to the blockage display unit LM as before, but this time the subscriber b corresponding unit sets it to a logical value of 1 indicating the blockage state. Transfer destination subscriber number extraction unit
TNF is not activated, but the called party blocked post-processing unit BP is started to execute predetermined post-processing, and the called party blocked signal is sent back to the trunk line TL2. The response processing unit ANS of the central processing unit CPB, which received the signal via the communication channel network SWB, returns a called subscriber blockage signal to the trunk line TL1, and also sends an absent subscriber empty transfer processing unit TIR.
Activated and the empty block display part was changed to logical value 1 once.
Return the subscriber c corresponding section of the LM to a logical value of 0. Similarly, the response processing unit ANS of the central processing unit CPA, which has received the called party blocked signal via the communication channel network SWA, returns the called party blocked signal to the calling party a, and also transfers the called party blocked signal to the absent subscriber. Subscriber b of the vacancy display unit LM that started the processing unit TIR and changed the logical value to 1
Return the corresponding part to logical value 0. As a result, the trunk line between stations A and B is prevented from being completely occupied by the call transfer call. Note that if subscriber c has not registered call forwarding, the local subscriber translation unit TLR of the central processing unit CPB converts the subscriber number nc as described above.
is transmitted to the called party blockage processing unit IBD, and the called party blockage processing unit IBD activates and calls the called party activation/calling unit IP or the called party blockage post-processing unit depending on the blockage status of subscriber c. Start BP. When the called party blocking post-processing unit BP is activated, the called party blocked signal is sent back to the trunk line TL1 as described above, and the absent subscriber empty transition processing unit TIR of the central processing unit CPA detects the blocked subscriber. Return the subscriber b corresponding section of the display section LM to logical value 0, and if the called party activation/calling section IP is activated, subscriber c
The response signal issued by is sent back to station A via trunk line TL1, and the central processing unit that received the response signal
The response processing section ANS of the CPA activates the absent subscriber idle transfer processing section TIR, and causes the subscriber b corresponding section of the idle display section LM to return to the logical value 0.

As is clear from the above explanation, according to this embodiment, even if subscribers b and c of other stations A and B mutually double-register as transfer destination subscribers, a call is received to subscriber b or c. Due to this call, trunk lines TL1 and TL2 between stations A and B are only temporarily occupied, and the trunk lines between stations A and B are prevented from being occupied indefinitely.

Further, as described above, setting the busy display section LM to the busy state until the busy state of the forwarding destination subscriber is known enables the next incoming call forwarding connection.

Now, subscriber a registers call forwarding with subscriber b as the destination subscriber, and at the same time, subscriber b registers call forwarding as subscriber c.
When subscriber d, not shown, makes a call to subscriber a while registering call forwarding as the forwarding destination subscriber, the call is forwarded to subscriber b using the same procedure as above, and then forwarded to subscriber c. Then, a call is made between subscriber d and subscriber c.

During the call, subscriber b cancels the call transfer registration for subscriber c, and when subscriber e, not shown, makes a call to subscriber a, the call is transferred to subscriber b.

This is because when subscriber d's call is forwarded to subscriber a and subscriber b one after another and then further forwarded to subscriber c, subscriber a and b are shown in the blockage display section LM.
This is because the corresponding part of is temporarily changed to a logical value of 1, but after the call transfer destination subscriber c is found to be in a busy state, it is returned to a logical value of 0. Even if the subscriber b corresponding section of the blockage display section LM becomes a logical value of 0, the subscriber a corresponding section of the blockage display section LM will forward calls for subscribers d and subscriber c. If the logical value remains at 1 during a call, subscriber e will not be connected to subscriber b because subscriber a is busy.

Note that FIG. 3 is only one embodiment of the present invention, and the target exchange is not limited to subscriber telephone exchanges, for example, and the present invention can also be applied to other exchanges such as telephone exchanges. The effect remains the same. It is also considered that the absent subscriber idle processing unit TIB and the absent subscriber idle transition processing unit TIR of the central processing units CPA and CPB may be realized by using a program together, but the effects of the present invention can also be achieved in such a case. remains unchanged.

As described above, according to the present invention, in an exchange equipped with a blockage display section and a call transfer section, even when subscribers of other stations mutually double register call transfers, the trunk line between both stations is unlimited due to call transfer calls. This prevents the communication between the two stations from being blocked, making it possible to designate a subscriber of another station as the transferee subscriber, thereby realizing a highly flexible call transfer system.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing an example of a conventional call forwarding system. Figure 1 shows a case where the forwarding destination subscriber is in the same station as the absent subscriber, and Figure 2 shows a case where the subscriber at two stations forwards the call. FIG. 3 is a diagram illustrating a call transfer system according to an embodiment of the present invention. In the figure, a, b and c are subscribers, nb and nc are subscriber numbers, SW, SWA and SWB are communication channel networks, MM, MMA and MMB are main storage devices, CPU, CPA and CPB are central processing units,
SFB and SFC are subscriber files, LM is a blockage indicator, T is a call diversion registration indicator, TN is a forwarding subscriber number, SSR is a subscriber number receiver, PTL is a received digit translator, and RS is an outbound route. Determination unit, TLR is local subscriber translation unit, TNF is transfer destination subscriber number extraction unit, IBD
is the called party blockage processing unit, IP is the called party activation/calling unit, BP is the called party blockage post-processing unit, ANS is the response processing unit, TIB is the absent subscriber blockage processing unit, and TIR is the missed subscriber blockage processing unit. A and B are stations, and TL1 and TL2 are trunk lines.

Claims (1)

[Scope of Claims] 1. In an exchange equipped with an idle display section that indicates the idle status of each accommodated subscriber and a function of automatically forwarding an incoming call to an absent subscriber to a forwarding destination subscriber, When a call is received by a subscriber who requested call forwarding when the busy display shows an empty indication and the subscriber is not present, the subscriber receives a blocked signal or a response signal while the call forwarding is in progress. The call transfer method is characterized in that temporary blockage processing means TIB and TIR are provided for maintaining the blockage display section of the subscriber who has requested the call transfer in a blockage display until the call transfer is requested.