KR100314316B1 - A method for providing multibell-service using impulse ratio - Google Patents

Abstract

The present invention relates to a communication method that makes it possible to easily distinguish who the receiver is by generating various bells using an intermittent ratio. In the present invention, the VST protocol is applied to the PSTN exchanger and the RT so that one EN By operating multiple DNs in a network, it is possible to distinguish recipients of an incoming call on an existing single line and at least one telephone (terminal). In addition, it is possible to implement a network interworking technology in the existing switching network and digital subscriber network, at least three or more that can be applied to the switch-subscriber network-terminal delay elements to the minimum, and to export various melodies, music, etc. of the terminal By providing an input signal, by implementing a technology for identifying exactly who the recipient is, it facilitates the convenience and privacy of the communication.

Description

How to provide multi-bell service using enforcement ratio. {A METHOD FOR PROVIDING MULTIBELL-SERVICE USING IMPULSE RATIO}

The present invention relates to a communication method for easily distinguishing who the receiver is by generating various bells using an interruption ratio, and distinguishing a receiver for an incoming call on an existing single line and at least one telephone (terminal). This would be possible. In addition, it is possible to implement a network interworking technology in the existing switching network and digital subscriber network, and to apply a minimum of the exchange-subscriber network-terminal delay (PDD: Post Dialing-Delay), various melody, music, etc. of the terminal It provides at least three or more input signals that can be exported.

In the related art, various methods for distinguishing recipients have been proposed, which are largely a method according to a terminal having a receiver selection function (Korean Patent Application No. 98-019488) and a method according to providing a specific call signal at an exchange (Korean Patent Application No. 96-028627). Presented.

In the case of the terminal having the above-described receiver selection function, the announcement can be made through the memory of the telephone station or the terminal, and the receiver can be selected without pressing a button using voice recognition technology. However, in case of using a telephone station, i.e., an existing communication network, a user needs to perform a work in direct connection with a communication network operator. In addition, every change of recipient information must be reported directly to the telephone company, and the telephone company must change it, and thus cannot provide convenience for both the operator and the user. Furthermore, it was a problem in terms of time and money.

On the other hand, in the case of using the memory of the user terminal, the problem with the above changes can be solved, but there is a problem that the user has an economic burden because the cost of the terminal increases.

On the other hand, in the case of the method of distinguishing a receiver according to the provision of a specific call signal in the latter exchange, the cost burden such as replacing an exchange of an existing communication network enterprise is increased, and the ease of use in that the user must recognize the password. Does not have

The present invention is a technology for ensuring the smoothness of the call and the privacy of the individual by easily identifying the receiver by distinguishing the receiver with a ringing sound in the terminal used by many as described above.

1 is a configuration diagram of a communication network according to the present invention;

2 is a flow chart for providing a multi-bell service according to the present invention;

3 is a block diagram showing a signal flow in the present invention;

4 is a map illustrating a physical C-channel timeslot allocation principle according to the present invention;

5 is a block diagram showing a protocol configuration according to the present invention;

6 is a map showing a protocol frame format according to the present invention;

7 is a map showing the structure of a LAPV5DL sublayer according to the present invention;

8 is a map showing the structure of a LAPV5DL sublayer header according to the present invention; and

9 is a map showing a multi-bell control ratio according to the present invention.

The present invention relates to a communication service for distinguishing a recipient, which can be easily distinguished by assigning a plurality of numbers to a single line and providing various ring tones.

In the conventional telephone number assignment method, since the physical number EN (equipment number) is called and the DN (directory number) used as the actual telephone number works in a 1: 1 connection. However, it is not possible to assign multiple DNs to one EN.

On the other hand, in the present invention, the PSTN (Personal Switched Telephone Network) in FIG. 1 showing the overall network configuration, hereinafter referred to as PSTN) exchanger and RT (Remote Terminal; subscriber transmission device, hereinafter RT) By applying the V5.2 protocol, multiple DNs can be applied to a single EN. In other words, the existing telephone number is designated as the representative number (D1) and directly used in conjunction with the EN. The physical number (EN) is configured to allow the PSTN exchanger to apply the representative number (D1) and the physical number (EN) when sending the additional numbers (D2, D3 ...). In other words, when the added value added D3 ..) is sent out, the existing telephone network is used as it is.

Meanwhile, in the conventional technology, only the EN is managed within the exchange itself and the signal processing is directly processed by the exchange. However, in the present invention, the V5 protocol is applied so that the exchange manages only the virtual EN and transmits only the information about the port number in RT. Thus, the RT directly processes the EN corresponding to the port number provided in the RT.

The flow of ringtone provision according to the invention is shown in FIG. 2.

When the receiving exchange receives an incoming call number (a) from the calling exchange (1), the receiving exchange checks the corresponding ring type (0-4) according to the incoming call number through a search of the subscriber database (2). After that, whether the V5.2 is subscribed or not, the real subscriber and the V5.2 subscriber directly connected to the exchange are distinguished and processed (3). If the recipient of the incoming telephone number is a V5.2 subscriber, the V5.2 message including the ringtone is transmitted to the subscriber network equipment (4). On the exchange side, the subscriber network equipment receiving the V5.2 message containing the corresponding ring tone-RT-in this case is the terminal of the confirmed receiver and the current with the interruption ratio corresponding to the ring type (1 ~ 4) is sent to the called terminal. Transmission (6). Accordingly, the called terminal receiving the interrupted current from the RT converts the received current into the corresponding ring tone (7). In the case of the telephone number identified as a solid subscriber in step (3), since V5.2 is not used, the telephone number is directly transmitted to the called terminal with a current having an interruption ratio (5). On the other hand, if the multi-bell service is not applied, it is inputted separately at the receiving side exchange, so that the existing call signal is transmitted directly to the terminal without going through such a path.

Overall signaling in accordance with one embodiment of the present invention is shown in FIG. 3. When the caller receives the dialed number 101 from the PSTN exchanger and transmits an AL (Allocation) signal 102 to the RT, the RT processes this and then the AC (Allocation Complete) signal 103 Is sent back to the PSTN exchange. The PSTN exchanger receiving the AC signal transmits an EC (Establish Cadensed-ring (CR)) signal 104 to RT again, and the RT receiving the EC signal sends a call signal 105 to the receiver and sends an EA to the PSTN exchange. When the (Establish Acknowledge) signal 106 is transmitted, the PSTN exchange receiving the EA signal sends a ring-back tone 107 to the caller. At this time, the RT receives a hook-off signal 108 from the receiver side and transmits it to the PSTN exchange 109. The currency is then established. The signal transmitted at this time will be described in detail below.

In the case of the existing V5.1, VB.1 used only in the 1E1 link without supporting the aggregation function (bearer channel connection protocol), ISDN primary rate connection and communication channel (C-channel) protection. 2 supports the aggregation function, ISDN main access, and protection of the communication channel, and supports up to 16E1 link. The frame structure of V5.2 at this time is as shown in FIG.

When an interface consists of one link, it is divided into two types. First, when only one C-channel is used, TS (Time Slot) 16 is used. Second, if two or three C-channels are used, use TS16, 15, 31. On the other hand, when the interface consists of two or more links, a protection protocol is used and is included in TS 16 of the 16th second link of the primary link. If more C-channels are needed, this is done in the following order. ① Allocates to TS16 of remaining link in order. ② Assign to TS15 of one link. ③ If more, it is allocated to TS31 of the same link. (4) Then, it continues until TS15,31 of all links are allocated in order of TS15,31 of next link.

In addition, the V5.2 protocol has the structure of FIG. 5, and as shown, bearer channel (PCB), Pulse Code Modulation (PCM) coded from PSTN user port, 64kbit / s information from ISDN user port, as shown. Bidirectional transmission capability of allocated B-channel and H-channel, ISDN D-channel information, PSTN signaling information, user port control, 2048kbit / s link control information, Layer 2 link control information, protection switching information, and bearer channel connection information Has

On the other hand, the signal between the PSTN exchange and the RT is shown in Figure 6, and LAPV5-EF (Link Access Protocol for V5 interface-Envelope Function sublayer; It is represented by a frame. The basic LAPV-5 features include data link establishment and teardown, data forwarding, flow control, and error detection.

PSTN path state is different depending on AN and LE path as shown in Table 1.

AN's Path Contents AN0 When the restart procedure is performed by the system administrator (out of survice state) AN1 Inactive state, no call in progress, must have the ability to detect subscriber acquisition (null state) AN2 Subscriber acquisition is detected and a confirmation message passes to LE, waiting for EA from LE (path initiated by AN state) AN3 paper Regulating the confirmation message to prevent the overload of the LE caused by the subscriber's on-hook and then off-hook when the confirmation message is delivered to the LE but no EA message is received from the LE. Transition to AN1 state after protection cycle (path abort request state) AN4 Line information state while PSTN portline information is processed at the LE AN5 When the normal PSTN signaling function is active (path active state) AN6 If AN requires path disconnection to LE (port blocked state) LE's path LE0 When the restart procedure is performed by the system administrator (out of survice state) LE1 Inactive state, no call in progress, port null state LE2 Pass confirmation message to AN (path initiated by LE state) LE3 AN sends a confirmation message to LE and waits for EA from LE (path initiated by AN state) LE4 When the normal PSTN signaling function is active (path active state) LE5 LE requested path disconnect request state to AN LE6 AN asks LE to break path (port blocked state)

In this case, as shown in FIG. 6, the two-byte EFaddr (Envelope Function Address; EFaddr) and information (information), starting with 1 byte of flag, It has a 2-byte FCS (Frame Check Sequence), and another flag indicating a finish. Flags indicating the start and end of the dual signal, EFaddr and FCS are basically included in LAPV5-EF, where LAPV5-EF is generated / deleted / transparency of the flag and generated / deleted / extracted FCS, etc. It should be able to perform the function of. At this time, the flag identifies the frame boundary, and when there is no frame to transmit, the continuous flag is transmitted.

As shown in Table 2, the EFaddr is composed of 2 bytes. At this time, EA (Address Field Extention) indicates whether the address area is extended and is set to '0' if the next byte is an address area, or '1'. In LAPV5-EF, the EA of the first byte is set to '0' and the EA of the second byte is set to '1'. In addition, the address setting consists of 13 bits all, and 0 ~ 8175 in the range of 0 ~ 8192 is used to identify ISDN user port, 8176 ~ 8191 is reserved, and V5DLaddr (V5 Data Link address; V5DLaddr) Identify a DL (Data Link) layer service provided to Layer 3 with a value such as

In this case, the following four cases are discarded without notifying the transmitting side, and no operation is performed. ① When frame is 4 bytes or less between address field and end flag. ② When it is not composed of byte integer before binary 0 bit insertion or after extraction. ③ When there is an error in FCS, EFaddr is not composed of 2 bytes. In this case, (4) the receiver has an EFaddr that is not supported or EFaddr is not shown in Table 2, that is, it receives 7 or more consecutive bits '1'.

8 7 6 5 4 3 2 One byte EFaddr 0 EA0 One EFaddr (child) EA1 2

Only the information area of the LAPV5-EF is continuously changed during the transmission and reception, and the information at this time is two LAPV5-DL (LAPV5-Data Link sublayer; LAPV5 data link sublayer) depending on the presence or absence of the information area as shown in FIG. LAPV5-DL) is a frame structure, which is composed of an area of at least 3 and at most 533 bytes. The link address (2 bytes) and the control field (2 bytes) have the same structure as in the EFaddr case. In this case, the exchange should be able to detect the failure of the LAPV5-DL connection even if there are no frames transmitted on the data link after the data link is connected. In addition, the format of the link address field is shown in FIG. 8, and as mentioned above, V5DLaddr can be used from 8176 to 8191 in 13 bits, and is used to distinguish entities of the layer 3 protocol as shown in Table 3.

beat V5DLaddr 8 7 6 5 4 3 2 One One One One One One One C / R EA Byte 1 Byte 2 One One One 0 0 0 0 EA PSTN Protocol (8176) One One One 0 0 0 One EA Control Protocols (8177) One One One 0 0 One 0 EA BCC Protocol (8178) One One One 0 0 One One EA Protection Protocols (8179) One One One 0 One 0 0 EA Link Control Protocols (8180) All other numbers are reserved

In addition, as shown in Table 4, it is possible to distinguish whether a frame is a command frame or a response frame.

User side direction Network side ▶ C 0 ▶ R One C ◀ One R ◀ 0

On the other hand, when the LAPV5-DL frame is as follows, it is processed as an invalid frame. First, when the link address field is not 2 bytes. Second, when the receiver includes V5Darrd which is not supported. Third, when the control field includes the sequence number. It is smaller than byte.

The format of the control field is the same as the control field format defined in ITU-T (International Telecommunication Union-Telecommunication Standardization section; ITU-T) Q.921. The procedure for communicating information with the LAPV5-DL layer in the following paragraphs is also subject to the procedures set out in ITU-T Q.920 / Q.921. Meanwhile, only the request and indication procedure among the primitive between Physcal layer and layer 2 (Primary between Physical Layer and Layer 2) -DATA is used for information transmission with Layer 1. In other words, the activation / deactivation procedure or primitive of LAPV5 is not used. In addition, the AN's frame transmission procedure with LAPV5-DL uses only the multi-frame acknowledgment information technology among the three information delivery methods defined in LAPV5. That is, the unconfirmed information transmission and the access management entity information transmission of LAPV5 are not used. Furthermore, since LCIV5-DL has a fixed Data Link Connection Identifier (DLCI), the terminal endpoint identifier (TEI) management procedure of LAPV5 is not used. In addition, a FRMR (Frame Reject) response used to notify an error condition that cannot be recovered by retransmission of the same frame by the data link entity of the frame type and a DISC (Disconnect; connection) transmitted to terminate a multi-frame operation. Disconnection) Do not use auto negotiation of command and system parameters. Furthermore, the D-channel signal information of the ISDN subscriber is not mapped from the LAPV5-EF layer to the LAPV5-DL layer but to the data link layer of ITU-T Q.920 / Q.921.

Mapping is divided into four directions: First, in case of communication from LAPV5-EF to LAPV5-DL, the LAPV5-EF header is removed and the information area is transferred to the LAPV5-DL sublayer. Second, in case of communication from LAPV5-DL to LAPV5-EF, the same EFaddr is set as V5Daddr, and the LAPV5-DL frame is loaded in the information area of the LAPV5-EF plane and transmitted through the configured C-channel. Communication from the third AN frame to the LAPV5-EF sets the same EFaddr as the ISDN port address, and delivers the LAPD / LAPF frame to the information area of the LAPV5-EF frame through the configured C-channel. Fourth, communication from LAPV5-EF to AN frame removes the LAPV5-EF header and forwards it to the AN frame function for transmission to the designated ISDN user port.

The first byte of the information signal is a protocol identifier and all protocols use the same value of one byte ('01001000'), while the layer 3 address is a layer 3 protocol entity to which a message sent or received within the V5.2 interface applies. It is used for different protocols to identify the entity. In addition, the message type is used to identify the function of the message being sent or received, and the total message types used in the layer 3 protocol are shown in Table 5.

The fourth byte of the Layer 3 protocol indicates the message type. At this time, the 8th bit is always fixed as '0' and the direction that can be transmitted according to the remaining 7 bits.

beat Message type Direction (AN LE) 7 6 5 4 3 2 One 0 0 0 - - - - PSTN protocol message type 0 0 0 0 0 0 0 ESTABLISH BOTH 0 0 0 0 0 0 One ESTABLISH ACKNOWLEDGE BOTH 0 0 0 0 0 One 0 SIGNAL BOTH 0 0 0 0 0 One One SIGNAL ACKNOWLEDGE BOTH 0 0 0 One 0 0 0 DISCONNECT BOTH 0 0 0 One 0 0 One DISCONNECT ACKNOWLEDGE BOTH 0 0 0 One 0 One 0 STATUS ENQUIRY LE to AN 0 0 0 One One 0 One STATUS AN to LE 0 0 0 One One One 0 PROTOCOL PARAMETER LE to AN 0 0 One 0 - - - CONTROL protocol message type 0 0 One 0 0 0 0 PORT CONTROL BOTH 0 0 One 0 0 0 One PORT CONTROL ACKNOWLEDGE BOTH 0 0 One 0 0 One 0 COMMON CONTROL BOTH 0 0 One 0 0 One One COMMON CONTROL ACKNOWLEDGE BOTH 0 0 One One - - - PROTECTION protocol message type 0 0 One One 0 0 0 SWITCH-OVER REQUEST AN to LE 0 0 One One 0 0 One SWITCH-OVER COMMAND LE to AN 0 0 One One 0 One 0 OS SWITCH-OVER COMMAND LE to AN 0 0 One One 0 One One SWICTCH-OVER ACKNOWLEDGE AN to LE 0 0 One One One 0 0 SWITCH-OVER REJECT BOTH 0 0 One One One 0 One PROTOCOL ERROR AN to LE 0 0 One One One One 0 RESET SN COM BOTH 0 0 One One One One One RESET SN ACK BOTH 0 One 0 - - - - BCC protocol message type 0 One 0 0 0 0 0 ALLOCATION LE to AN 0 One 0 0 0 0 One ALLOCATION COMPLETE AN to LE 0 One 0 0 0 One 0 ALLOCATION REJECT AN to LE 0 One 0 0 0 One One DE-ALLOCATION LE to AN 0 One 0 0 One 0 0 DE-ALLOCATION COMPLETE AN to LE 0 One 0 0 One 0 One DE-ALLOCATION REJECT AN to LE 0 One 0 0 One One 0 AUDIT LE to AN 0 One 0 0 One One One AUDIT COMPLETE LE to AN 0 One 0 One 0 0 0 AN FAULT AN to LE 0 One 0 One 0 0 One AN FAULT ACKNOWLEDGE LE to AN 0 One 0 One 0 One 0 PROTOCOL ERROR AN to LE 0 One One 0 - - - LINK CONTROL Protocol Message Type 0 One One 0 0 0 0 LINK CONTROL BOTH 0 One One 0 0 0 One LINK CONTROL ACK BOTH All other numbers are reserved

And know the destination. For example, if a message of '00001110' is inputted, the PSTN exchange sends protocol parameter signals to RT.

On the other hand, other information elements include a single byte information element and a variable length information element. For variable length information elements, at least 3 bytes (information element identifier (1 byte) + length of information element content (1 byte) + information element content) (At least 1 byte). Layer 3 protocol global information element identifiers are shown in Table 6.

beat protocol Information element Length in bytes 8 7 6 5 4 3 2 One 0 - - - - - - - Variable-length information element 0 0 0 0 0 0 0 0 PSTN SEQUENCE NUMBER 3 0 0 0 0 0 0 0 One PSTN CADENCED RINGING 3 0 0 0 0 0 0 One 0 PSTN PULSED SIGNAL 3 ~ 5 0 0 0 0 0 0 One One PSTN STEADY SIGNAL 3 0 0 0 0 0 One 0 0 PSTN DIGIT SIGNAL 3 0 0 0 One 0 0 0 0 PSTN RECOGNITION TIME 4 0 0 0 One 0 0 0 One PSTN ENABLE AUTONOMOUS ACK 4 ~ 6 0 0 0 One 0 0 One 0 PSTN DISABLE AUTONOMOUS ACK 3 0 0 0 One 0 0 One One PSTN CAUSE 3 ~ 5 0 0 0 One 0 One 0 0 PSTN RESOURCE UNAVAILABLE 3 ~ 5 0 0 One 0 0 0 0 0 CONTROL CONTROL FUNCTION ELEMENT 3 0 0 One 0 0 0 0 One CONTROL CONTROL FUNCTION ID 3 0 0 One 0 0 0 One 0 CONTROL VARIANT 3 0 0 One 0 0 0 One One CONTROL INTERFACE ID 5 0 0 One One 0 0 0 0 LINK CONTROL LINK CONTROL FUNCTION 3 0 One 0 0 0 0 0 0 BCC USER PORT IDENTIFICATION 4 0 One 0 0 0 0 0 One BCC ISDN PORT CHANNEL IDENTIFICATION 3 0 One 0 0 0 0 One 0 BCC V5 TS IDENTIFICATION 4 0 One 0 0 0 0 One One BCC MULTI-SLOT MAP 11 0 One 0 0 0 One 0 0 BCC REJECT CAUSE 3 ~ 14 0 One 0 0 0 One 0 One BCC PROTOCOL ERROR CAUSE 3 ~ 5 0 One 0 0 0 One One 0 BCC CONNECTION INCOMPLETE 3 0 One 0 One 0 0 0 0 PROTECTION SEQUENCE NUMBER 3 0 One 0 One 0 0 0 One PROTECTION PHYSICAL C-CHANNEL IDENTIFICATION 4 0 One 0 One 0 0 One 0 PROTECTION REJECTION CAUSE 3 0 One 0 One 0 0 One One PROTECTION PROTOCOL ERROR CAUSE 3 ~ 5 One - - - - - - - Single byte information element One 0 0 0 X X X X PSTN LINE INFORMATION One One 0 0 One X X X X PSTN STATE One One 0 One 0 X X X X PSTN AUTONOMOUS SIGNALING SEQUENCE One One 0 One One X X X X PSTN SEQUENCE RESPONSE One One One 0 0 X X X X PSTN END OF PULSE (PULSE NOTIFICATION) One One One One 0 X X X X CONTROL PERFORMANCE GRADING One One One One One X X X X CONTROL REJECTION CAUSE One All other numbers are reserved

Some of the message type and information element identifiers in Tables 5 and 6 may not be used.

The required information is entered after the signal indicating the message type, and then there is a 1 byte signal that identifies the Cadence Ring. At this time, if a message of '00000001' is inputted, it is recognized as a cadence ring. The next one byte represents the data length of the cadence ring, and finally the ring type signal is designated as one byte. The cadence ring confirmation signal to the ring type signal is used only when the EC signal is transmitted from the PSTN exchange.

Table 7 shows additional service information for implementing a cadence ring. In the present invention, as shown in Table 7, it is made to implement different ring sounds that are already input to the user terminal by using the control ratio of the ring.

Meanwhile, the present invention uses the first pulse among the call signal interruption ratios, and minimizes the PDD by disposing different intervals of the first pulse for each multibell type. In addition, in order to harmonize the caller's RBT and the call signal, as shown in Table 7 below, in order to maintain the timing of the caller and the called party, it was applied in connection with 1 second and 2 seconds of the RBT.

Bit 1 meaning 7 6 5 4 3 2 One 0 0 0 0 0 0 0 2 seconds per second (basic call signal) 0 0 0 0 0 0 One 0.2 sec 0.4 sec (1st), 0.4 sec 1.0 sec (2nd) 0 0 0 0 0 One 0 0.4 seconds 0.6 seconds (1st), 0.4 seconds 1.6 seconds (2nd) 0 0 0 0 0 One One 0.6 seconds 0.6 seconds (1st), 1.2 seconds 0.6 seconds (2nd) 0 0 0 0 One 0 0 0.8 sec 0.4 sec (1st), 0.2 sec 1.6 sec (2nd) 0 0 0 0 One 0 One Establish without call All other numbers are reserved

The subscriber's off-hook and on-hook use fixed signal information elements and the hook-flash uses the 'resister recall' pulse type of the pulse signal information station. The multibell control ratio used at this time is shown in FIG.

When a recipient uses a number assigned to one telephone line, especially in households with households that want to ensure personal privacy, technology for identifying exactly who the recipient is is implemented to help ensure convenience and privacy of communication. do. In addition, in the present invention, since a unique number is assigned to individual recipients, the change of the exchange device or the change in the personal terminal by a method such as adding a number to the back of the existing number is almost eliminated, thereby costing both the user and the operator. This results in savings. On the other hand, in the case of the present invention, since a unique number of an individual is newly assigned, problems such as memory management required for a specific password or a guide message, as in the related art, are solved.

Claims (3)

In the multi-bell service providing method for distinguishing the receiver by using a PSTN switch, a subscriber station (RT) and a user terminal, A PSTN telephone exchange managing at least one number assigned to one communication line transmits signals of at least one or more different numbers to a subscriber station (RT) through a centralized terminal (COT) using the V5.2 protocol method. Doing; Converting a signal for one or more different numbers received from the PSTN exchanger into a current based on an interruption ratio in the subscriber transmitter (RT) generating at least one or more interruption ratios and transmitting the signal to a user terminal side; And Multi-bells characterized in that the user terminal to generate a different ringtone by different interruption ratio to generate the current transmitted from the subscriber station (RT) as a ringtone according to each interruption ratio to distinguish the receiver How we deliver the service. The method of claim 1, The PSTN switch in the step of transmitting a signal from the PSTN switch to the subscriber station (RT) applies a plurality of DNs to a single EN using a V5.2 protocol to apply a representative DN and an EN when requesting an added DN. To use an existing line, The PSTN exchange manages only the virtual EN, transmits only port information to the subscriber station RT, and transmits an EN corresponding to the port number provided in the subscriber station RT. The multi-bell service providing method characterized in that the direct processing. The method of claim 1, In the step of generating each of the current transmitted from the subscriber station (RT) as a ring tone according to the intermittent ratio, multi-bell service providing method characterized in that for generating a specific sound stored in accordance with the intermittent ratio to distinguish the receiver.