KR960013278B1 - Full electronic exchanger - Google Patents

Abstract

The method is for providing a way to send a third call while holding the existing call during connection. The method comprises the steps of: claiming a hold service; checking registration on a hold service demand in a digital call hold processing block; generating a sub-processor in call hold processing after checking the overload of the service system; claiming a transition to the value added service processor block; informing the completion of the call hold procedure; and resuming the call held after confirming the transition.

Description

How to Hold Digital Subscriber Call at Electronic Switching System

1 is a schematic diagram of an electron exchange system to which the present invention is applied.

2 is a digital basic call control procedure.

Figure 3a is a digital call flow control procedure according to the present invention.

3b is a digital call protection service provision review control procedure diagram,

Figure 3c is a digital call hold processing control process diagram.

3d is a digital call resume processing control procedure diagram.

4 is a diagram illustrating interworking between digital hobo-tablets.

The present invention relates to a digital subscriber call holding method in an electronic switching system which enables a digital subscriber to hold an existing call and make a third call in a digital environment of a distributed control system electronic switching center.

Protections function is a service that is already provided in the existing PSTN network and commercialized technology. On the other hand, due to the development of communication equipment, the plan to build a single network by absorbing (integrating) the existing network is being promoted globally under the proposition of the establishment of an integrated information and communication network (ISDN), which will be commercialized in the coming years. It is expected.

In line with this trend, the call-holding function provided in the existing voice exchange network should also be provided in the integrated information and communication network.

The necessity of the above function is not a requirement in the network but a requirement of the user (user), and the ability to send a new call to a subscriber in a call is an essential service for the user (user) using the voice exchange. There is an urgent need for a method of implementing the above functions in a digital environment of an electronic switching center to provide services to digital subscribers and to realize service interworking with an existing voice switching network (PSTN).

The present invention has been made in order to meet the above-mentioned demands, interlocked with various services provided in the existing voice switching network (PSTN), and an object of the present invention to provide a call hold processing method in the digital environment of the electronic switchboard.

In order to achieve the above object, the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a hardware structure diagram of an electronic switching system to which the present invention is applied, and is composed of three subsystems of a Central Control Subsystem (CCS), an Access Switching Subsystem (ASS), and an Interconnection Network Subsystem (INS). Looking at it as follows.

ASS is connected to analog and digital subscriber line and relay line, and is responsible for analog / digital conversion, time slot exchange, call processing, and ASS self-preservation at the end. ASS exists in one function but at the application stage, it can be used as ASS-S (analog subscriber), ASS-I (digital subscriber), ASS-7 (trunk), ASS-7 (trunk No.7), ASS-P (packet), etc. They can be classified and can be combined in various forms with the previous four forms.

The INS is responsible for message communication between ASSs or between ASS and CCS and is located at the center of the system. Up to 60 ASSs can be connected by optical fiber, and they are in charge of space switch and network.

The CCS system is a sub-system in charge of overall operation preservation. It is responsible for system operation, test and measurement, statistics and mass storage management, various input / output device control, and data channel connection with other systems.

Subsystem ASS is the target for implementing digital subscriber (ISDN) call hold function in an electronic switch having this hardware structure. A digital call waiting service software block (DSSC Digital Subscriber Service Control) is installed in the ASS to interact with existing basic call service blocks to provide digital call waiting service.

First, the basic procedure of basic call processing in the structure described above is described, and then the present invention will be described. The software blocks required for the digital basic call processing of the electronic switch are digital circuit control (DCC), user part control (UPC), number translation (NTR), and route control (RCO).

The NTR is loaded into the INS subsystem and the remaining blocks are loaded into the ASS subsystem. Various request and response messages sent from the digital subscriber are delivered to the DCC block, which examines each message and processes it according to the message content (request).

2 is a digital basic call control procedure.

The basic call processing will be examined on the premise of the Enbloc method (see CCITT Recommendation Q.931). When the DCC block receives the SETUP message from the calling subscriber, it checks whether the requested call is Speech, obtains the called number, sends the station code translation request (PfxTransRQ) to the NTR block, and sends the IntCallRP from the NTR block. Receive. Then, when the calling DCC block makes a call number translation request (CdNoTransRQ) to the NTR block, the NTR makes a call occupancy request (DigCdSubsSzRQ) to the called DCC block. After that, the incoming DCC block makes a request for outgoing information (DinCglnfoRQ). In the outgoing call, the voice switch (time switch, space switch) is connected and the incoming call attribute value is transmitted (DigCglnfoRP). Each DCC block that is notified of the originating information sends a SETUP message to the incoming digital subscriber to notify the incoming call. The incoming DCC block then receives an ALERT and CONNECT message from the incoming digital subscriber and sends it to the originating DCC block and the call enters the call state. In the call state, the call release can be released by any of the originating and incoming digital subscribers, and the DCC block receiving the release notification is notified to the counterpart DCC block (DigCgRelRP, DigCdRelRP) to complete the call release. When applied to the Open System Interconnection seven-layer model, the content mentioned so far belongs to the three-layer model, and a small amount of three-layer DSSC blocks DCC blocks and UPC blocks without modification of the two-tier or less entity (hardware and software) are applied. In order to provide a digital call hold processing method.

The digital subscriber call hold service provides one digital hold call per B channel for the Basic Rate Interface 28 + D and the protocol applied to the subscriber-network interface is functional (see Functional: CCITT Recommendation Q.932). This method is presented on the assumption of protocol.

The processing procedures necessary to implement digital protection flow processing can be divided into digital call protection service request, service justification review, and service processing.

3A is a digital call waiting service request control procedure diagram.

When the DCC block receives a HOLD message from a subscriber who is currently busy, the DCC block makes an invocation to the DSSC block, which is a digital call hold processing block, and the self (process) is destroyed.

Figure 3b is a digital call hold service justification review control procedure.

DSSC block that received digital call service request first checks the contents of database to check whether digital call service is activated, and the number of call numbers assigned to the subscriber's channel is limited (1 channel per B channel). In this case, the DSSC_main process in the digital call processing block generates child processes (DSSC_HoldCtrlOrg, DSSC_Hold CtrlTerm) to handle the digital call holding process.

3C is a digital call hold processing control procedure diagram.

Assume that subscriber A is a digital call-holding service subscriber and wants to put a call on hold with subscriber B.

When the digital call waiting service request is legally processed, the DSSC block receives the request for transition to the supplementary service processing block (DigSubsSvcRQ) and the supplementary service processing block transition acknowledgment (DigSubsSvcACK) to the other party's basic call control block (DCC, UPC). Wait until When receiving the confirmation notification from the counterpart DSSC block, the corresponding B channel is released and the callback request subscriber is notified of the call pending (HOLD ACK), and the counterpart DSSC block of the counterpart subscriber provides a holding tone to the counterpart subscriber. Notifies you that it is complete.

3d is a diagram illustrating a process of processing a digital wait call response after an existing call is suspended.

If the subscriber who requested call hold wants to re-call a held call, if the request for RETRIEVE is requested, the DSSC block reassigns the B channel, notifies the other party of the re-call (HoldToneRelRQ), and transitions to the basic call processing block. When the request is received (NormChngRQ) and the control stream waits for the confirmation notification (NormChngACK), it notifies the RETRIEVEACK and transfers the control to the basic call DCC to complete the call resumption.

4 is a diagram for explaining interworking with a PSTN network.

The interworking with the voice switching network is designed so that the digital call hold control block (DSSC) takes charge of message conversion between the voice switching network and the integrated telecommunication network without any change or modification to the voice switching network. In the analog environment (PSTN) in the electronic switchboard, the blocks to be interlocked with the digital call block are ASC (Analog Subscriber Control), TKC (Trunk Contort), and TPC (Telephony Part Control). A total of five linkages were considered by linking analog and digital environments.

As described above, the present invention improves the diversification of the electronic switchboard providing service by applying it to the electronic switchboard, and realizes the modular blockchain service by maintaining the modularity of the software system by realizing it as an independent block (DSSC). It is easy to apply (transplant) to electronic switch, and call processing function is interdependent among other blocks, and to interwork with existing voice switching network (PSTN), it does not modify existing voice switching network in accordance with the step of network evolution. The DSSC block can be processed to achieve smooth interworking with the voice switching network.

Claims (1)

A call holding method applied to an electronic switch having three subsystems of a Central Control Subsystem (CCS), an Access Switching Subsystem (ASS), and an Interconnection Net-work Subsystem (INS). Receiving a service processing request to the digital call waiting processing block and waiting for itself to be destroyed; A second step in which the digital call hold processing block receiving the digital call hold service request checks the contents of the database to confirm whether the call hold service is registered; A third step of determining whether the number of calls allocated to the subscriber line is less than or equal to a set value, or whether the system state is not overloaded, to generate each processor in the call hold process; A fourth step of making a transition request to a supplementary service processing block to the counterpart party basic call control block when the digital call holding service request is legally processed; A fifth step of releasing the corresponding B channel when receiving the additional service processing block transition confirmation and notifying the call hold requestee of the call holding request adviser by providing the call subscriber with a call holding tone to notify the completion of the call holding; If the subscriber who requested the call hold wants to re-call the held call, if the call is requested to be resumed, the channel is reassigned and the re-call is notified to the other party's control block and the transition request is sent to the basic call processing block. The method of holding a digital subscriber call in an electronic switchgear, characterized in that it comprises a sixth step of completing the call release after receiving notification of the call release confirmation.