JPH04255152A - Digital conference talking system - Google Patents

Abstract

PURPOSE:To attain conference talking to plural subscribers and to accommodate them to the system by providing two branch insertion circuits to a connector and converting a time slot of a PCM primary group signal given to them mutually. CONSTITUTION:A cross connect device 21 implements time slot conversion and gives the result to 1st and 2nd PCM primary group signals A,B of each of branch insert circuits 5-1-5-3, and since the content of signals in time slots L,M,N is the same, conference talking is attained freely among subscribers 3-2,3-3, 3-11-3-13 and the connection device 1-11 accommodates the plural subscribers 3-1-3-13 as conference available subscribers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital conference system that connects subscribers using PCM signals and allows conference calls between a plurality of subscribers.

0002

2. Description of the Related Art As shown in the block diagram of FIG. Subscribers 3-1 to 3-3 to 1 to 1-3
Each subscriber 3-
Conference calls between 1 and 3-3 are to be held.

FIG. 3 is a block diagram showing the branch/add circuits in the connection devices 1-1 to 1-3, and shows the first and second P
Each predetermined time slot of CM primary group signals A and B, and the third
An adder 4- having a time slot selection function is used to mutually branch and insert the PCM primary group signal C of the
1 to 4-3 are provided. In this case, the PCM primary group signal C is used to connect the circuit between subscribers, and the PCM primary group signal A is connected to the circuit between the subscribers.
, B to communicate with other subscribers.

0004

[Problem to be solved by the invention] However, the PC in Fig. 3
The number of subscribers to be connected as M1 order group signal C is only one line, and in order to connect multiple subscribers so that conference calls can be made,
Since the structure of the adders 4-1 to 4-3 is complicated, there is a drawback that each of the connecting devices 1-1 to 1-3 shown in FIG. 2 can accommodate only one subscriber line each.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a digital conference call system in which a single connection device can accommodate a plurality of subscribers for conference calls.

[0006]

[Means for Solving the Problems] The present invention provides a connection device having at least two add/drop circuits as shown in FIG. A cross that provides a PCM primary group signal, converts a predetermined time slot in this signal to another time slot, and provides it as the first and second PCM primary group signals to the second add/drop circuit in the connection device. A connection device is provided.

[0007]

[Operation] The cross-connect device performs time slot conversion and provides it as the first and second PCM primary group signals of each drop/add circuit, but the signals in the time slots in which each drop/add circuit performs drop and add have the same content. Therefore, subscribers accommodated in each add/drop circuit in the connection device can freely make conference calls with each other.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the block diagram of FIG. 1 showing an embodiment. In the figure, connection device 1
-11 in which the first and second branch/insert circuits 5-1, 5-
2 and accommodates subscribers 3-11 to 3-13, and a cross-connect device (hereinafter referred to as a connect device)
21 and each connection device 1-2 and 1-11 are PCM primary group signals (hereinafter referred to as primary group) 6-1 to 6-3 in the transmission path.
are connected in a loop. In addition, connection device 1-
2 to 1-4 are the same as in the case of FIG.

[0009] Here, the subscriber 3-11 is in the primary group 6
-3 time slot (hereinafter referred to as TS) L, and this TS・L is connected to the TS・M in the connect device 21.
is converted into the add/drop circuit 5-3 of the connecting device 1-2 as the first and second linear groups A and B, and is further converted to the add/drop circuit 5-1 of the connecting device 1-11. The predetermined TS/M is given as the first and second primary groups A and B, and the predetermined TS/M of these is set to other TS/N in the connect device 21.
is converted into the connecting device 1-11 via the connecting device 1-2.
The first and second primary groups A
,B, then the TS/N of this is the connecting device 1
-3 is connected to subscriber 3-3.

Therefore, each branch/add circuit 5-1 to 5-
3 is the same as in Figure 3, each one TS M, N and subscriber 3
-2, 3-12, 3-13 can be added and dropped individually, and since the content of each TS L, M, and N signal is the same, each subscriber 3-2, 3-3, 3-1
Conference calls can be made freely between subscribers 1 to 3-13, and the connection device 1-11 can accommodate a plurality of subscribers 3-11 to 3-13 for conference calls.

[0011]

According to the present invention, a connecting device is provided with at least two branch/add circuits, and the time slots of the PCM primary group signals given to each circuit are mutually converted in the cross-connect device. Although the present invention uses an add/drop circuit that handles one time slot, it is possible to accommodate a plurality of subscribers in the same connection device so that they can make a conference call, so a remarkable effect can be obtained in digital conference calls.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional example.

FIG. 3 is a block diagram of a drop/add circuit.

[Explanation of symbols]

1-2 to 1-4, 1-11 Connection device 3-2, 3-3
, 3-11 to 3-13 Subscribers 5-1 to 5-3 Add/drop circuits 6-1 to 6-3 PCM primary group signal 21 Cross-connect devices L to N Time slots

Claims (1)

[Claims] 1. A connection device comprising at least two add/drop circuits for mutually branching and inserting respective predetermined time slots of first and second PCM primary group signals and a third PCM primary group signal; The first and second PCM primary group signals are supplied to a first add/drop circuit in the connecting device, and a predetermined time slot in this signal is converted to another time slot, and the second branch in the connecting device A digital conference call system comprising: a cross-connect device that supplies the first and second PCM primary group signals to an insertion circuit.