KR0132948B1 - Method for trilateral voice call service in n-isdn digital - Google Patents

Abstract

The present invention satisfies the N-ISDN user-network access signaling in a narrowband ISDN exchange (hereinafter referred to as N-ISDN) and is capable of accepting functional protocols (basic match subscriber, primary group match subscriber, basic access). A method for processing digital three-way service in an exchange for N-ISDN, which holds one subscriber to another subscriber and transfers another subscriber's call from a busy state to a three-way call. -It is applicable to all N-ISDN exchanges using ISDN subscriber-network signaling, and the N-ISD N terminal has the effect that the service can be provided without the addition of existing functions.

Description

Digital Three-Telephony Service Processing Method in N-ISDN Switch

1 is a schematic structural diagram of an all-electronic exchanger which is a distributed control system to which the present invention is applied;

2 is a flow chart of a basic call received from an N-ISDN exchange to a digital subscriber B (CR1).

FIG. 3 is a diagram illustrating a process within the network when the called party B (CR1) puts a busy A-B (CR1) subscriber on hold.

4 is a procedure showing the creation and destruction of a processor in the network until the call of the incoming B (CR1) is suspended;

5 is a transition diagram of a control process in a network when a B (CR2) subscriber tries to make a three-party call while holding a call of an incoming B (CR1),

6 through 8 illustrate a digital three call service processing flow chart according to the present invention.

The present invention satisfies the N-ISDN user-network access signaling in a narrowband ISDN exchange (hereinafter referred to as N-ISDN) and is capable of accepting functional protocols (basic match subscriber, primary group match subscriber, basic access). The present invention relates to a digital three-way service processing method in an exchange for N-ISDN, which holds one subscriber to another subscriber and transfers another subscriber's call from a busy state to a three-way call.

In general, the three-way calling service provided to a subscriber using an analog connection in a conventional public switched telephone network (PSTN) is a commercial technology.

However, in establishing N-ISDN as a single network by absorbing the existing network, the existing tri-telephony service does not satisfy the connection standard between N-ISDN subscriber-network, so the signal transmission channel between subscriber and network is not provided separately. Only limited amount of service can be provided by the audible sound through the information transmission channel, and unlike the public switched telephone network (PSTN), there is a problem in that the N-ISDN is not applicable because the access specification between the subscriber and the exchange period is different.

In addition, since the conventional technology is provided to subscribers using only audible sound, it is impossible to provide a service to data mode terminals other than a telephone, so that a service can be provided for all N-ISDN access terminals such as telephone and data, There is a need for a method of implementing a trilateral currency function of a new technology that can accommodate a functional protocol that is advantageous in standardizing the use of supplementary services.

The present invention has been made in order to solve the problems of the prior art, it is possible to make a three-way call in the busy state by holding another call (Hold) to the N-ISDN subscriber to hold (Hold) The purpose of the present invention is to provide a digital three-way service processing method in an N-ISDN exchange that realizes service interworking with an existing PSTN network.

In order to achieve the above object, the present invention provides a digital tri-currency service process applied to an electronic switch having an ASS (Access Switching Subsystem), an INS (Interconnection Network Subsystem), and a SubSystem (Central Control Subsystem). In the method, the digital tri-currency processing block receiving the digital tri-currency service request as an outmost process controlling the tri-currency service is a first step of checking whether the digital tri-currency service is registered by searching the contents of the database. ; The Digital Three-Call Processing Block that receives the Digital Three-Call Service Request as the Outmost Process that controls the Three-Call Service, creates a Child Process dedicated to controlling the Three-Call Service and requests itself to be released from the Subscriber. The second step; stopping and returning the process of Compute various data to communicate with the process controlling the child, calculate various data to communicate with the processor controlling subscriber A (optionally set up subscribers A, B, and C), connect a pending sound to subscriber A, and A third step of requesting the control process on the subscriber A side to connect the call path of C and stopping and returning its own process upon request of release from the subscriber; The child process is a control process of the subscriber, CR1, and if there is no service transition response, the busy subscriber CR2 transfers the control to the basic call processing block and returns to the basic call processing block when there is no response. step; The child process receives the service transition response by requesting the control transition of the subscriber B (CR1) and receives the service transition response from the on-call subscriber C (CR2) and receives the service control transition response. The fifth step of requesting the allocation of the three-way call equipment after disconnection; after the C subscriber and the CMX (Conference Mixer) are released using the special service code [* 14] during the three-way call, the child process is connected to the subscriber B (CR1). A sixth step of requesting for resumption of the call to resume and its own process to be destroyed and returned; If subscriber A (CR1) requests a call release during a three-way call, the child process releases all CMX and then reassigns channel B for resumption, notifies subscriber B (CR2) of the re-call, and transitions to the basic call processing block. A seventh step of making a request and receiving the confirmation notification from the control stream, and after the notification of the call resume confirmation, transfers control to the basic call processing block and returns to the quantum call; If subscriber C (CR2) requests a call release during a three-way call, the child process releases all CMX and then the child process requests to resume to call to subscriber B (CR1) and its own process is destroyed and returned. Characterized in that it comprises eight steps.

Briefly described the gist of the present invention.

The present invention can be applied to a private exchange that satisfies the N-ISDN subscriber-network interface, and can realize the digital subscriber tri-call function without modification of the basic network in consideration of the interworking with the existing voice switching network (PSTN). Based on the recommendations of the CCITT, it can be easily applied to N-ISDN exchanges that satisfy the N-ISDN subscriber-network signaling. In addition, since the present invention implements the function as one independent block, it is independent of the block to perform other functions to maintain the call processing function and efficiency, thereby improving the modularity of the software system.

In addition, when performing the three-way call function in the existing PSTN network, the subscriber of the three-way call function did not know whether the call was properly connected or disconnected when the three-way call was completed, but in the N-ISDN network, the LCD (Liquid Crystal Display) of the subscriber station was used. By providing the service success message, the user can visually check, and when the failure of the three-way service fails, the subscriber can take an active action by using the LCD of the terminal and further improve the quality of the three-way service. Let's do it.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

FIG. 1 is a schematic structural diagram of an electronic switching system to which the present invention is applied and includes three sub-systems of an access switching subsystem (ASS), an interconnection network subsystem (INS), and a central control subsystem (CCS).

The ASS includes a subscriber and trunk interface, a time switch, various signaling devices, a packet handler, etc. to perform most call processing functions and self functions, and thus has a horizontally distributed structure.

In addition, up to 60 ASSs can be connected, and the ASS in the source state exists as one, but in the application stage, ASS_S (SubsCR1ber), ASS_I (ISDN SubsCR1ber), ASS_T (Trunk), and ASS_7 (No.7 Signaling System) In ASS_S, the ASP (Access Switching Processor) handles the call processing function for subscribers and ISDN subscribers accommodated in the exchange, ASP is the No.7 signal in the ASS_T. ASP and Signaling Message Handling Processor (SMHP) perform the functions of a message transfer part (MTP) and a signaling connection control part (SCCP).

In the INS, a number translation processor, a routing control function, and a space division switch control function, which are call processing functions commonly required in each ASS, are performed by a number translation processor (NTP) and an interconnection network processor (INP). And maintenance function data channel connection function with other systems.

The target for implementing the digital subscriber (ISDN) subscriber's three-party call function in the electronic switch of the above-described hardware structure is the subsystem ASS, and the existing digital multi-way call (DMULC), which is a digital three-way processing software block, is installed in the ASS. It interacts with basic call service blocks to provide digital three call service.

When the digital three-way call function is implemented, the three-way call is made while the existing call is withheld and the new subscriber is in a busy state.

The software blocks required for digital basic call processing of electronic switching system are DCC (Digital Circuit Control), UPC (User Part Control), NTR (Number TRanslation), RCO (Rute COntrol), and GSC to connect Call Mixer. There is a Global Service Control block. Where NTR is mounted in the INS subsystem and the remaining blocks are mounted in the ASS subsystem. Various request and connect messages sent from the digital subscriber are delivered to the DCC block, and the DCC block examines each message and processes the message according to the message content (request).

FIG. 2 is a flow chart of a basic call received from the N-ISDN exchange to the digital subscriber B. The basic call processing will be described on the premise of the Enbloc method (see CCITT Recommendation Q.931).

The calling DCC-a block that receives the SETUP message from the calling subscriber A (sub-A) checks whether the requested call is a speech, obtains the called number, and requests translation of the station number into the NTR block (Pfx TransRQ). And receive IntCallRP or OutgoingCallRP from NTR block.

The originating DCC-a block then makes a call number translation request (CdNoTransRQ) to the NTR block, and the NTR block makes a call occupancy request (DigCdSubsSzRQ) to the incoming DCC-b block. After that, the incoming DCC-b block makes the outgoing information request (DigCgInfoRQ) to the outgoing DCC-a block. In the outgoing call, the voice switch (time switch, space switch) is connected and the incoming call attribute value is transmitted (DigCgInfoRP).

The incoming DCC-b block notified of the originating information sends a SETUP message to the incoming digital subscriber B (sub-B) to notify the incoming call.

The incoming DCC-b block then sends an ALERT and CONNECT message from the incoming digital subscriber B (sub-B) to the originating DCC-a block and the call enters the call state. In a call state, call release can be released from any of the originating and incoming digital subscribers, and the DCC block receiving the disconnection notification (DICONNECT) is notified to the other DCC block (DigCgRelRP, DigCdRelRP) to complete the call release. RELEASE, REL COMP).

FIG. 3 is a flowchart of the process inside the network when the receiving subscriber B (sub-B) puts a busy calling subscriber (sub-A) in a hold state. DSSC-a is a calling subscriber from DCC-a. An additional service processing block that inherits control of A (sub-A), and DSSC-b (CR1) inherits control between the source subscriber A (sub-A) and the destination subscriber B (sub-B) from the DCC-b. Represents each received additional service processing block.

First, when the digital subscriber B (sub-B) presses the hold key, the sub-B receives a hold message from the DCC-b of the subscriber subscriber (sub-B), and the DSSC (Digital SubsCR1ber) is a supplementary service call-hold transition block. The HoldRQCS message is sent to the Service Control block and the (DCC Process) is destroyed.

The DSSC-b receiving the supplementary service transition request message receives the processor identification number of the terminating DCC and stops the terminating DCC-b using a primitive of the CROS (Concurrent Real Time Operating System) provided by the electronic switchboard. (STOP) and create your own child process to pass control.

The newly created incoming DSSC-b (CR1) block sends a Service Transition Request (SubsSvcRQ) message to the originating DCC-a block, and the originating DCC-a block sends a Supplementary Service Transition Request (DigSubsSvcCtrlRQ) message to the originating DSSC-a.

In the same way as in the outgoing DSSC-a, the originating DCC-a block is destroyed and control is transferred to the originating DSSC-a block.

The newly created DSSC-a sends a service transition confirmation message (SubsSvcACK) to the destination DSSC-b (CR1) block, and the destination DSSC-b (CR1) block receives the message and sends a hold confirmation message (HoldAckCI) to the called party. Send and receive HoldToneConnRQ messages and Subscriber Service Notifications (SubsSvcRP) to the outgoing DSSC-a block.

When the outgoing DSSC-a receives the request for the connection of the holding tone, it releases the existing time switch and connects the holding tone (HoldTone) to the calling subscriber to control the supplementary service between the digital calling / receiving subscribers (sub-A, sub-B) (CR1). It is placed in a pending state controlled by the block DSSC.

As described above, the call holding method of FIGS. 2 and 3 is basically designed in the same concept as that provided in the PSTN. However, unlike the PSTN network, which uses only the keypad protocol, it uses a functional protocol. It is now possible to hold a basic call using a hold key.

In addition, as the terminal becomes intelligent, two (2B + D) call reference numbers can be managed, and accordingly, the implementation method in the network with a new concept different from the PSTN will be described from FIG. .

FIG. 4 is a flowchart illustrating processor creation and destruction in the network until the call of the incoming B (CR1) is suspended. FIG. 4 is a simplified diagram of FIG. 2 and FIG. It is shown schematically.

As shown in the figure, during normal calls between digital subscribers (sub-A, sub-B) (CR1), the DCC controls them and the control processor in the network when the called subscriber B (sub-B) puts a call on hold. The control transfers from the DCC to the DSSC block and the DCC block is destroyed.

5 is a transition diagram of a control process in a network when a B (CR2) subscriber tries to make a three-party call while holding a call of an incoming B (CR1), and the existing subscriber AB (sub-A, sub-B The process until the subscriber B (sub-B) (CR2) attempts a three-way call by calling a new incoming call in the pending state between (CR1) is shown in terms of process creation in the network.

Since the terminal can manage two (2B + D) call reference numbers, subscriber B (CR2) sends a call setup (SETUP) message to the network to call a new called subscriber C. In the network, the existing DSSC-b DCC-b (CR2), which is a completely separate process from (CR1), is newly generated to control subscriber B (CR2). In the newly created subscriber B (CR2), the control procedure between the new calling party DCC-b (CR2) and the new called party C (DCC-c) is the same as in FIG.

If a three-way call is requested during a call between a new subscriber B (CR2) and C (DCC-c), control of the subscriber B (CR2) -C is transferred to DSSC-b (CR2), which is an additional service control block, and DCC- The b (CR2) block is destroyed. Subscriber B (DR2) finally takes control back to DMULC block that directly controls the three-way call, DSSC-b (CR2) block is destroyed and two processors (CR1, CR2) are created to control subscriber B in the network. Subscribers A and C each have one process controlling them.

6 through 8 are flow charts of the digital three call service according to the present invention.

6A to 6B show CR1 (call reference number 1) on hold and CR2 (call reference number 2) indicates that the calling party B (CR2) attempts to make a three-way call during a call. This is the process procedure after using).

DCC-b (CR2) is a basic call processing block controlling subscriber B with subscriber B's second call reference number (CR2), and DSSC-b (CR2) controls subscriber B from the DCC-b (CR2). Is a supplementary service processing block inherited by the DMULC is a three-party call service processing block inherited from the control of the subscriber B from the DSSC-b (CR2), DCC-c is a basic call processing block responsible for the control of the subscriber, DSSC-c Indicates an additional service processing block inherited from the control of the subscriber C from the DCC-c.

When the subscriber B (CR2) digits the function request code (InformIC [* 34 *]) for the trilateral call, the DCC-b (CR2) block receives it and sends an information message (InformCS) to the DSSC-b (CR2). It is inherited and the DCC-b (CR2) block is destroyed. DSSC-b (CR2) makes a number translation request (PfxTransRQ) to NTR block and NTR block makes special service code notification (SsOpCodeRP) to DSSC-b (CR2) block. DSSC-b (CR2) makes special service code (SsOpCodeRP) ), If it is a digital three call service, the three call service request (DigTWCSvcRQ) is made to the DMULC block, and the DSSC-b (CR2) block is destroyed.

The DMULC block, a three-party call processing block, sends a service transition notification (PairSvcRP) to a reserved DSSC-b (CR1) block, and the DSSC-b (CR1) block receives a signal and notifies the call reference number (PairSvcRPAck) to the DMULC block. The block analyzes this and stores the necessary call reference (CR) numbers.

The DSSC-b (CR1) sends a subscriber service transition notification (SubsSvcRP) to the calling subscriber DSSC-a. The DMULC block makes a Subscriber Service Transition Request (SubsSvcRQ) to the DCC-c and the DCC-c makes a Subscriber Service Transition Request (DigSubsSvcCtrlRQ) to the DSSC-c, which is an additional service processing block, and the DSSC-c sends a service confirmation message to the DMULC block; (SubsSvcACK) is notified and DCC-c is destroyed.

The control between B (CR2) -C (DSSC-c) subscribers and DSSC-b (CR1) of subscribers of AB (CR1) plays the role of relaying to DSSC-a, and the DMULC block is led by B (CR2). It controls the connection and disconnection of the tri-AC service. The DMULC block requests to release the existing busy switch (AltSwChRelRQ) and converts the CMX (Conference Mixer) to the Global Service Control (GSC) block in order to convert the B (CR2) -C busy call into a three-way call. Do If the GSC block sends a CMX connection notification (CmxConnRP) that the CMX is connected to the DMULC block, the DMULC block releases all information connecting the general call between ABs, and then connects the spatial switch of the called party to the CMX and the DMULC block is the DSSC-b. When the switch information change request (SwInfoChngRQ) is made to the (CR1) block, the DSSC-b (CR1) block is relayed back to the DSSC-a block, and the DSSC-a releases the existing switch information, and then connects the spatial switch and the CMX to the calling party. Do it.

DMULC and DSSC-a are connected through CMX, and the pending sound continues to be transmitted, and the DMULC block makes a CMX (Conference Mixer) connection request (CmxConnRQ) to the GSC block in order to connect the CMX between B (CR2) and C. When the GSC block sends a CMX connection notification (CmxConnRP) to the DMULC block, the DMULC block sends a CMX channel notification (CmxChRP) to the DSSC-c block, and the DSSC-c block changes the existing switch information to the CMX channel.

In the DMULC block, if the voice switch (time switch, space switch) is connected and the DSSC-b (CR1) block is used to request the hold sound release (HoldToneRelRQ), the DSSC-b (CR1) is again requested to release the hold sound to the DSSC-a block. The HoldToneRelRQ) is relayed to release the A subscriber's hold sound, connect the voice switch (time switch, space switch), and form a complete three-way path between ABCs. Control process of A and C subscribers represented in the above description DCC and DSSC play the same role in ASC and SSCO in PSTN network, and subscriber A and C subscriber are N if only three-telephone function subscribers satisfy N-ISDN access protocol. -It is possible to interwork with PSTN network because it is designed considering enough in N-ISDN to enable interworking even if it is not ISDN.

7A to 7B are flowcharts of a method for releasing a C subscriber (final call subscriber) using a function request code [* 14 *] during a three-way call.

When subscriber B (CR2) presses the function request code [* 14 *] during the three-way call, the DMULC block makes a number translation request (PfxTransRQ) to the NTR block, and the NTR block makes a special service code notification (SsOpCodeRP) to the DMULC block. If the service code is other than the TWC_rel after analyzing the special service code, the DMULC block remains in the trilateral call after deleting the request code, and the request to release the three-way call request (TWC_rel) from the NTR block. When notified, send a CMX Release Request (CmxRelRQ) to the GSC block to release all CMX.

The DMULC block sends the Release Release Notification (DigCgRelRP) to the DSSC-c block and the Resume Notification (PairRetrieveRP) to the DSSC-b (CR1) releases all information of the DMULC block and the DSSC-c block and destroys each block. .

The DSSC-b (CR1) releases all the switch information connected to the CMX after receiving the resumption notification (PairRetrieveRP), and then makes a switch channel connection request (SwChConnRQ) to the SNC in order to connect the switch by a general call. When the SNC sends a switch channel connection notification (SwChConnRP) to the DSSC-b (CR1) block, the DSSC-b (CR1) block connects the voice switch (time switch and space switch) and requests the basic call to be changed to DSSC-a, the calling party. Norm ChngRQ). DSSC-a block connects voice switch (time switch, space switch) and makes control request (NormDCCCtrlRQ) to DCC-a which controls basic call processing block and DSSC-a block is destroyed. DCC-a makes a change confirmation request (NormChngACK) to DSSC-b (CR1), which is a called party, and DSSC-b makes a bilateral call (AB) when a control request (NormDCCCtrlRQ) is made to DCC-b, a basic call processing block. Control passes to the DCC block, which is the basic call processing block, and the DSSC-b block is destroyed.

8 is a state transition flow diagram based on the implementation of DMULC software, which is a three-way call service processing block according to the present invention, which is a skeleton of the concept of the flow diagram to guide the actual source program.

When a three-party service request comes to an outmost process that controls the three-party call service (801), the parent process creates a party process dedicated to the three-party service request, so that subscribers B2 (CR2) and subscriber C call. While monitoring infinitely the request of the three-way call service (DigTWCSvcRQ) during the service request signal is received, it takes over control from the DSSC controlling the additional service and creates a three-party call control processor that performs the three-way call service control ( 702).

By exchanging information (call reference number) with the B (CR1) subscriber of the DSSC on the other side of the pending subscriber (703), the connection request is controlled by an actual call to realize a three-way call. The party process releases the existing call path (704), requests a three-party call equipment assignment (705), and forms a three-party call after releasing the held tone of the held subscriber (706). When the terminating subscriber or the calling party of the relay call requests the release of the three-way call, the CMX and the corresponding call path are released, and when the calling subscriber requests the release, the CMX and the call path of all the subscribers in the call are controlled and released (707).

In the case of a three-way call service, up to three people can make a three-way call. When a new subscriber requests a service during a three-way call (708), the existing third party (CR2) is released and the existing callers are held with each service call. The new subscriber is added to the call by adding a three person call equipment.

As described above, according to the present invention, it is applicable to all N-ISDN exchangers using N-ISDN subscriber-network signaling of the International Standard (CCITT), and the N-ISDN terminal device can receive a service without adding an existing function. It can be effective.

Claims (1)

A method of processing a digital three call service applied to an electronic switch having an ASS (Access Switching Subsystem), an INS (Interconnection Network Subsystem), and a Central Control Subsystem (CCS) SubSystem. The digital tri-currency processing block, which receives the digital tri-currency service request as an outmost process, checks whether the digital tri-currency service is registered by searching the contents of the database; As a process that controls the three-way service, the digital three-way processing block that receives the digital three-way service request creates a child process dedicated to the three-way service control and requests its release from the subscriber. A second step of stopping and returning to the process; The child process calculates various data for communicating with the process controlling the subscriber, calculates various data for communicating with the processor controlling subscriber A (optionally, subscribers A, B, and C set up), and attaches a pending sound to subscriber A. A third step of requesting the control process on the subscriber A side to connect subscriber A and the call path of the subscriber C and stopping and returning its process upon request of release from the subscriber; The child process is a control process of the subscriber, CR1, and if there is no service transition response, the busy subscriber CR2 transfers the control to the basic call processing block and returns to the basic call processing block when there is no response. step; The child process is a control process of a subscriber B (CR1) that receives a service transition request by receiving a service transition response and receives a service transition request from a caller (CR2) subscriber C and receives a service control transition response. A fifth step of requesting three-party telephone equipment allocation after disconnecting; After releasing CMX and CMX (Conference Mixer) using the special service code [* 14] during the three-way call, the child process makes a request to resume the call to subscriber B (CR1), and the own process is destroyed and returned. A sixth step; If subscriber A (CR1) requests a call release during a three-way call, the child process releases all CMX and then reassigns the B channel for resumption of the call, notifies subscriber B (CR2) of the re-call, and the basic call processing block. A seventh step of requesting a transition request and receiving a confirmation notification from the control transition, and after receiving notification of call resumption confirmation, transfers control to the basic call processing block after returning to a quantum call and returns; If subscriber C (CR2) requests a call release during a three-way call, the child process releases all CMX, then the child process requests resumption to resume call to subscriber B (CR1), and its own process is destroyed and returned. A digital three-way service processing method in a switch for a narrowband general information network (N-ISDN), comprising eight steps.