JPH0728342B2 - Digital branch trunk for photo broadcast connection - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a digital branch trunk for photo broadcast connections in a time division switching system.

[Background of the Invention]

1 (a) and 1 (b) are diagrams showing the system configuration of each connection state of the photo broadcast connection system by manual connection in the conventional time division exchange system. In FIGS. 1A and 1B, 1 is a relay line such as a dedicated line connected to a photo broadcast source, 2 is a trunk, 3 is an exchange, 4 is a relay stand, 5 is an interface device, and 6 is A photo receiver, 7 is a trunk for an interface of a relay line of another station such as a branch line, and 8 to 12 are set connection paths in the communication network.

With this configuration, when a photo sender connected to the trunk line 1 in FIG. 1 (a) receives a call from the trunk 2, the exchange 3 closes the connection path 8 in the communication network and relays the trunk line 1. Connect to the stand 4. In response to this, the handler of the relay stand 4 knows that the call is a broadcast relay connection call to other stations, including the own station of the photograph, and closes the connection path 9 by operating the relay key of the relay stand 4 or the like. The photo receiver 6 is captured through the interface device 5, the connection path 10 is closed to capture the interface trunk 7 of the relay line of another station such as a branch line, and the partner station is activated by voice or dial information. When the other station knows that it is the photo reception information based on this information, it captures and activates the photo receiver through its own exchange (not shown). When the photographic receiver is activated, it sends out a response signal of an in-band frequency assigned to itself. Photo receiver 6 of exchange 3
Similarly sends a response signal. These response signals are detected by the relay stand 4, and the operator of the relay stand 4 is notified by a visible / audible display. If the destination of the relay line of another station such as a branch line is multiple broadcast connections, response signals with different in-band frequencies are returned for each broadcast target station by the number of broadcast connection destinations. Notify the handler of the relay stand 4 with a plurality of visible / audible displays. When the operator of the relay stand 4 confirms this display and knows that all the connection destination response signals have been returned, he / she opens the connection paths 8, 9 and 10 sequentially by operating the key of the relay stand 4, etc. The connection paths 11 and 12 in the communication path network shown in FIG. 1B are closed to disconnect the relay stand 4, and in this state, the photograph transmission information is received and relayed.

Thus, according to the conventional method, the operator intervenes many times for one connection call, such as setting / releasing the connection paths 8, 9, 10 and setting the connection paths 11, 12 in the exchange. However, the processing procedure in the storage program type switching system is complicated and diversified.

Further, in order to eliminate the above-mentioned inconvenience, it is effective to use a branch trunk so as to double-connect the own photo receiver and the like in hardware and to appropriately connect the incoming line to the branch trunk. However, as the branch trunk,
By using a digital branch trunk that simply performs n-1 addition, an analog signal with a high signal level, such as photographic information, is μ low (law) PCM coded
Addition of -1 may exceed the quantization level of 8 bits, that is, 256 steps, and the normal input signal may be greatly distorted in some cases.

[Object of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved digital branch trunk for photo broadcast connection in which the number of broadcast connection path settings in the time division switching system is reduced and the software processing procedure can be simplified.

[Outline of Invention]

The present invention stops the simultaneous connection of a plurality of terminal devices by changing the connection path setting in the communication path network of the exchange, and makes the terminal devices necessary for the photo information relay connection to be dually connected in hardware by using a branch trunk to receive an incoming call. Focusing on the peculiarity of the transmission signal direction to realize branching without exceeding the 8-bit or 256-step quantization step, as a branch trunk that enables broadcast connection simply by connecting the line to this branch trunk, As a calculation method, the transmission direction is a simple n-1 branch without addition, while the reception direction is a branch to one specific branch point.
This is a digital branch trunk for photo broadcast connection made possible by branching n-1 additions.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. FIGS. 2 (a) and 2 (b) are system configuration diagrams in each connection state showing one embodiment of a photo broadcast connection system using a photo branching digital branch trunk for the time division switching system according to the present invention. is there. 2 (a) and 2 (b), the same reference numerals as those in FIG. 1 denote the same or corresponding parts, 13 is a digital branch trunk according to the present invention, and 14 to 18 are set connections in the communication network. It's a pass.

With this configuration, when the photo transmission source station connected by the trunk line 1 such as the dedicated line of FIG. 2 (a) is activated, the exchange 3 closes the connection path 14 in the communication network and opens the trunk 2. The passed photo transmission source relay line 1 is connected to the relay stand 4. In response to this, the handler of the relay stand 4 receives a connection request for transferring the photo information to another station such as a branch office, closes the connection path 15 by operating the electronic key of the relay stand 4, and captures the branch trunk 13. , The connection path 16 is closed, the trunk 7 is captured, and the branch line such as a branch line is activated. In the case of the photo information broadcast connection including the own station, one branch trunk 13 is connected to the photo receiver 6 of the own station through a connection path 17 via the interface device 5 dedicated to the photo receiver 6. In this state, the connection destination station (not shown) responds to the activation of the trunk line of another station such as a branch line, and responds to the activation by a dial or voice information, and captures its own photo receiver when it knows that it is a photo reception request. to start. When this photo receiver is activated, it returns a response signal of a specific in-band frequency assigned to itself as a connection completion signal. This response signal is returned to the branch trunk 13 via the trunk line of the other station such as a branch line, the trunk 7 and the connection path 16.
The response signal from the photo receiver 6 of the exchange 3 is also returned to the branch trunk 13 via the interface device 5 and the connection path 17. The branch trunk 13 transfers the response signal to the relay stand 4 via the connection path 15 via the built-in digital adder circuit. In the relay stand 4, the response signal is identified by the detector, the corresponding partner station display lamp is turned on, and the response signal is sent from the monitor circuit such as a speaker. If the operator of the relay stand 4 confirms this state and decides that the photograph may be sent, after notifying the photograph sender, the connection paths 14 and 15 are released by operating the electronic key or the like. Second
The connection path 18 shown in FIG. 7B is closed, intervention of the handling operation is stopped to prepare for the next connection request, and in this state, the photo information is received and relayed. Further, in the digital branch trunk 13, in the case of a system in which the connection state and the operation state are divided into several stages like the picture transmission and the operation is advanced while transmitting and receiving the response signal each time, the response signal is generally at the voice level. In comparison, its transmission level is transmitted at a height of 2 to 3 times. Further, in the case of the photo broadcast connection, it is assumed that a plurality of such response signals are returned simultaneously. Therefore, in the method of adding n-1 to all branch points as in the conventional branch trunk, for example, in the case of three branches, the formula becomes A + B + C- (A or B or C), and n
There is a possibility that the quantization stage represented by the 8-bit code may be exceeded at the time when the numbers are added, and in some cases the regular input signal may be greatly distorted. According to the present invention, attention is paid to the peculiarity of the transmission signal direction in order to realize branching without exceeding such a quantization step of 8 bits, that is, 256 steps, and as a calculation method, the transmission direction, that is, the broadcast destination is calculated. For each, as a simple n-1 addition-less branch state,
While only the photo information is broadcast, the receiving direction, that is,
To the relay stand, a response signal from each of the broadcast transmission destinations is sent as a branch state of n-1 addition. As a result, distortion-free photo information can be transmitted to each broadcast destination. Further, although there is a fear that a distorted response signal is sent to the relay stand, even if a distorted response signal is sent, no particular trouble occurs.

FIG. 3 is a block diagram showing the concept of computing conditions of an embodiment of the digital branch trunk 13 for photo broadcast connection according to the present invention. In FIG. 3, 19 is a branch without addition in the transmission direction in the branch trunk 13, 20 is a branch with n-1 addition to only one specific branch point in the reception direction, and 21 is its addition circuit.

With this configuration, the main branch trunk 13 includes a decompressing unit, a computing unit, a compressing unit, etc. for the μ-low PCM code, and the computation conditions are as shown in the connection path 15 (18) and from the connection paths 16 and 17. In the photo information transmission direction, while branching 19 without addition,
In the receiving direction of the return signal from the connection paths 16 and 17 to the connection path 15 (18), the adder circuit 21 is provided with a storage device for adding n-1 to only one specific branch point. As a result, the addition conditions are relaxed, high-level signal branching is possible, and cost reduction can be expected by simplifying the arithmetic circuit.

FIG. 4 is a block diagram showing the concept of computing conditions of another embodiment of the digital branch trunk 13 for photo broadcast connection according to the present invention. In FIG. 4, 22 is a switching device, 23 is a switching control terminal thereof, 24 is an n-1 adder circuit for all branch points of the conventional system, and 25 is an n-1 adder circuit for only one specific branch point according to the present invention. .

With this configuration, by the switching control signal input to the switching control terminal 23 of the switching device 22, all branch points n-1 adding circuit 24 connected to the connection paths 15 (18), 16, 17 and only one specific branch point n
-Switch to the -1 addition circuit 25. Thus, the functions of the conventional branch trunk and the branch trunk according to the present invention can be easily compatible with each other. Therefore, it is not necessary to separately provide two types of branch trunks for a station with a relatively small call volume of two types, one for general conferences and one for photo broadcasting connection, and it is economical and space-saving. It is advantageous.

〔The invention's effect〕

As described above, according to the digital branch trunk for photo broadcast connection of the present invention, the number of times of switching the connection path at the time of one photo information broadcast relay can be reduced as compared with the conventional system. As a result, the program can be processed by a simple general connection routine with few state transitions, which is effective in simplifying the program processing and reducing the number of processing steps. In addition, branching can be performed without exceeding the quantization step of 8 bits or 256 steps. Since it can be realized, it is effective in improving the quality of the system.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are system configuration diagrams illustrating respective connection states of a conventional photo broadcast connection system, and FIGS. 2 (a) and 2 (b) are digital branches for photo broadcast connection according to the present invention. FIG. 3 is a system configuration diagram showing each connection state of an embodiment of a photo broadcast connection system using a trunk, and FIG. 3 is a block diagram showing a calculation concept of an embodiment of a digital branch trunk for photo broadcast connection according to the present invention, FIG. 4 is a block diagram showing the calculation concept of another embodiment. 1 ... Relay line, 2 ... Trunk, 3 ... Exchange, 4 ...
Relay stand, 5 ... Interface device, 6 ... Photo receiver, 7 ... Trunk, 13 ... Digital branch trunk,
14 to 18 …… Set connection path, 19 …… Branch without addition in the sending direction in the branch trunk, 20 …… Branch with n-1 addition to only one specific branch point in the receiving direction, 21 …… Adder circuit, 22 ... Switching device, 23 ... Switching control terminal, 24 ...
N-1 adder circuit for all branch points, 25 ... 1 n-1 only for specific branch points
Adder circuit.

Claims (2)

[Claims] 1. A μ-low PCM code for branching and distributing digitally encoded photo information to a photo receiver of its own station and a relay line of another broadcast destination at the same time in a time division switching system for photo broadcast connection. In a digital branch trunk for photo-broadcast connection, which comprises an expansion unit, a calculation unit and a compression unit, one specific branch point input is used as another branch point output as a calculation condition for the calculation unit in the photo information transmission direction. Along with the above-mentioned photo receiver of the own station and the return signal received from the relay line of the broadcast destination other station, the sum of all input signals of other branch points is output as one specific branch point Only to one specific branch point A digital branch trunk for photo-broadcast connection, which is equipped with the n-1 adder circuit. 2. A μ-low PCM code for branching and distributing digitally encoded photo information to a photo receiver of its own station and a relay line of a broadcast destination other station at the same time in a time division switching system for photo broadcast connection. In a digital branch trunk for photo-broadcast connection, which comprises an expansion unit, a calculation unit and a compression unit, one specific branch point input is used as another branch point output as a calculation condition for the calculation unit in the photo information transmission direction. Along with the above-mentioned photo receiver of the own station and the return signal received from the relay line of the broadcast destination other station, the sum of all input signals of other branch points is output as one specific branch point Only to one specific branch point N-1 adder circuit, a n-1 adder circuit for all branch points for general meetings, and a switching circuit for switching both of the above adder circuits by a switching control signal are provided. Branch trunk.