JPS6286998A - System for plural calls in multiparty line - Google Patents

Abstract

PURPOSE:To execute plural calls at any times when even the channel between the calling station and the called station which is to be called is not closed by providing the transmitting circuit classified by the direction, the receiving circuit classified by the direction, the changing-over circuit and the control circuit. CONSTITUTION:When a telephone set 2 as a calling station calls a telephone set 3 as a called station, the dial signal as the line control signal is sent from a transmitting circuit 20 classified by direction of the telephone set 3, the dial signal is inputted to a receiving circuit 30 classified by direction of the telephone set 3 and simultaneously, inputted to the receiving circuit 30 classified by the direction of telephone sets 4-6. At such a time, the receiving circuit 30 classified by the direction, by collating the address and the dial signal set beforehand, can discriminate whether or not the own station is the called station. At the time of the coincidence with the address, the receiving circuit 30 classified by the direction informs a control circuit 50 of the coincidence, and the control circuit 50 rings the bell of the telephone set 3 for the own station. Since the dial signal comes from the receiving circuit 30 classified by the direction, the control circuit 50 of the telephone set 3 can recognize that the circuit is called in the direction of the telephone set 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a multi-call system on a multi-party line, and more particularly, on a set of 4-wire lines, without using a multiplexed highway. The present invention relates to a multiple call system that enables multiple calls.

[Conventional technology]

Traditionally, in this type of non-multiplexed leased line, telephones are connected multi-drop to a transmitting and receiving set of 4-wire circuits, and each telephone is assigned an individual and unique address. ing. That is, the calling station dials the address of the called station that it wants to call, and sends this dial information to the sending line of the four-wire line.

At this time, all other telephones connected to the 4-wire line receive this dial information, and if it matches the address of their own station, they recognize that their own station is the called station. Ring the telephone bell. When the called station goes off-hook, a line connection is established and a conversation between the calling party and the called party is possible. Typically, dialing information, i.e., address, off-hook, and other signaling information is transmitted using a multi-frequency code (Multi-frequency code).
tiFrequencyCode) is used.

[Problem that the invention seeks to solve]

In the above-mentioned telephone line system that allows called party selection on a non-multiplexed multiparty line, any one
When a call is being made between Mi's calling station and called station, the call is also transmitted to other telephones with multi-party connections. However, because that telephone was not selected, no line connection was made between them. However, since the multiparty line is not multiplexed using PCM or FDM, there is a drawback that even if a call request occurs between other telephones in this state, this call request cannot be satisfied.

[Means for solving problems]

In order to eliminate such drawbacks, the present invention provides a direction-specific transmission circuit that transmits dial signals in each direction, a direction-specific reception circuit that receives line control signals in each direction, and a line control circuit that transmits dial signals in each direction. This system includes a switching circuit for connecting and transmitting/receiving, and a control circuit that controls this switching circuit to disconnect multiparty lines in directions unrelated to telephone calls.

[Effect]

In the present invention, as long as the path between the calling station and the desired called station is not blocked, any number of these calls can be made.

〔Example〕

FIG. 1 shows an embodiment of a telephone that is applied to a multi-call system on a multi-party line according to the present invention.

FIG. 2 is a general configuration diagram of a multiple call system in a multiparty line. In FIG. 1, 10.20 is a transmission circuit for each direction, 30.40 is a reception circuit for each direction, 50 is a control circuit, 60.70 is a selector as a switching circuit, 6
1,71 is the common terminal of selector 60.70, 62.63
．． 72.73 is the contact point of selector 60.70, Tl, T4
is an input terminal, T2. T3 is an output terminal.

In FIG. 2, each telephone set 2 to 6 is connected to one multiparty line 1. In FIG. In addition, Figure 1 shows 54
This shows a case where a multiparty line is set up using a PCM signal of kb/s.

Next, the operation of this multiple call system will be explained. First, the initial state will be explained. Multiparty line 1 is call-free in all parts, and selector 6 of telephone 3
The common terminal 61°71 of 0.70 is connected to the contact 62.72 side, and the selector 60.70 of the telephone 4°5 is also connected in the same way. In the case of the telephone 2 to which the subscriber wishes to send a dial signal, that is, the telephone 2 as the calling station, the common terminal 61.71 of the selector 60.70 is connected to the contact 63.
．． It is connected to the 73 side.

In this connection state, telephone 2 as the calling station
When calling the telephone 3 as the called station, the dial signal as a line control signal is sent to the direction-specific transmission circuit 2 of the telephone 2.
This dial signal is input to the direction-specific receiving circuit 30 of the telephone 3, and at the same time, the dial signal is sent from the telephone 4 to
The signal is input to the direction-specific receiving circuit 30 of No. 6. At this time, the direction-based receiving circuit 30 can determine whether the local station is the called station by comparing the dial signal with a preset address. When the address matches, the direction-specific receiving circuit 30 informs the control circuit 5 that there is a match.
0, and the control circuit 50 rings the bell of the telephone 3 of its own station. The control circuit 50 of the telephone 3 includes a direction-specific reception circuit 30
Since the dial signal is coming from the direction of the telephone 2, it can be recognized that the call came from the direction of the telephone 2. In the telephone 3, when a person hears the ringing of the telephone 3 and picks up the receiver, the control circuit 5
0 connects the common terminal 61 of the selector 60 to the contact 63,
The direction-specific transmitting circuit 10 issues a signal sending command. As a result, the directional transmitting circuit 10 sends an answer signal to the telephone set 2. When telephone set 2 receives the answer signal, a line for communication between telephone set 2 and telephone set 3 is established, and they can communicate with each other.

Next, the telephone 3 connects the common terminal 71 of the selector 70 and the contact 7
3 is connected, an answer signal is sent from the direction-specific transmission circuit 20, and the telephones m4 to m6 are notified of this state. Selector 7
By keeping 0 in this state, the multiparty line is disconnected. In this state, the phone 4
It is possible to make a call between the telephone 6 and the telephone 6. That is, telephone 2
．． Telephone 4 can recognize that the multiparty line in 3 directions is busy, but that the direction of telephones 5 and 6 is idle and that the multiparty line is disconnected from the call between telephones 2 and 3. Phone 4 and Phone 6
It is possible to make calls between

Next, the communication operation between the telephones 4 and 6 will be explained. When phone m4 makes a call to phone 6, first, phone 4
The common terminal 61 of the selector 60 is connected to the contact 63 side, and dial signals are sent from the directional transmitting circuit 10 to the three directions of the telephone.

After a predetermined time, the telephone 3 sends a message to the telephone 4 indicating that the line is in the BUSY state. This shows that the telephone 3 is BUSY.

Next, the control circuit 50 of the telephone 4 connects the common terminal 71 of the selector 70 to the contact 73, and sends out a dial signal from the directional transmitting circuit 20. Directional receiving circuits 40 of telephones 5 and 6 receive this dial signal. telephone 6
The direction-specific receiving circuit 40 compares the predetermined address with the received dial signal, and if they match, it notifies the control circuit 50 that the local station is the called station. Thereafter, operations similar to those described above are performed, and a call is established.

Each telephone does not need to be configured as to how the entire line is connected or how many telephones are connected. In FIGS. 1 and 2, telephone 2
Although the case where five stations 6 to 6 are connected to one multiparty line is shown, it does not matter how many stations are connected as long as each station can be identified by its address.

When multiple calls are made between arbitrary telephones and other call requests occur, the station where the call request occurred sends a dial signal in both directions, and an answer signal is returned from a certain station. If you receive a call, you can talk to that station.

However, as mentioned above, if other stations are BUSY,
B after the timer of the BUSY station finishes its operation.
The US Y signal returns. This is also possible because each telephone has a transmitting circuit and a receiving circuit for each direction.

Note that in this embodiment, the multiparty line is 64
Although the case of the k b /sOPCMUgJ line has been shown, it is clear that similar effects can be obtained even when a multi-party system is formed in the voice line. Also,
By inserting a branch line, telephones 2 and 3
．． Furthermore, it is also possible to make calls between the telephones 5 and 6 independently of the calls between the telephones 4 and 4.

〔Effect of the invention〕

As explained above, the present invention connects a line only between a direction-specific transmission circuit that transmits dial signals in each direction, a direction-specific reception circuit that receives line control signals in each direction, and any telephone that is currently talking. By providing a switching circuit for transmitting and receiving, and a control circuit that controls this switching circuit to disconnect multiparty lines in directions unrelated to calls, the system can be configured with a single multiparty line. Nevertheless, as long as the path between the calling station and the desired called station is not blocked, any number of these calls can be made.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of a telephone that constitutes a multiple call system on a multi-party line according to the present invention, and FIG. 2 is a diagram showing the overall configuration of a multiple call system on a multi-party line. 1...Multi-party line, 2-6...Telephone, 10.20...Directional transmission circuit, 30.40...
... Direction-specific reception circuit, 50 ... Control circuit, 60.7
0...Selector, 61.71...Common terminal, 6
2,63,72.73...Contact, TI, T4...
- Input terminal, T2. T3...Output terminal. Patent applicant: NEC Corporation Miyagi NEC Corporation

Claims (1)

[Claims] A direction-specific transmission circuit that transmits dial signals in each direction, a direction-specific reception circuit that receives line control signals in each direction, and a switching circuit that connects lines and performs transmission and reception only between arbitrary telephones that are in use. A multiple call system on a multi-party line, comprising a control circuit that controls the switching circuit to disconnect a multi-party line in a direction unrelated to the call.