JPH03252296A - Time division electronic exchange - Google Patents

Abstract

PURPOSE:To eliminate need for resynchronization of a system even when a terminal equipment is changed over by connecting a synchronizing signal transmission circuit to a specific channel of a time division switch and connecting the terminal equipment and the time division switch synchronously with a synchronizing signal of the time division switch. CONSTITUTION:When a synchronizing signal transmission circuit 101 is connected to a specific channel of a time division switch 2, the circuit 101 sends a frame while increasing the count by one for each frame. Through the constitution above, the frame number is identified by monitoring the count of the specific channel to distinguish the frame. Terminal interface circuits 20-22 make connections 31-33 by a time division switch to monitor the frame number and the communication with synchronization even at a speed of 8kbps or below is implemented. Thus, when the terminal equipment 40 interrupts the communication with the terminal equipment 42 is started, the system synchronization between the circuits 21 and 22 is taken, no out-of-synchronism takes place for the terminal equipments 41, 42 according to connections 36, 37. Thus, resynchronization of the system is not required.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a time-sharing electronic switching device.

[Conventional technology]

Conventionally, this time-division electronic switching equipment handles PCM audio coded signals, so it has performed synchronization at 8 Kbps, but has not particularly performed system synchronization at 8 Kbps or less.

[Problem to be solved by the invention]

-L The conventional time-sharing electronic switching equipment described above does not particularly perform system synchronization at speeds below 8 bps, and is configured to synchronize between connected terminals, so each time the terminals are connected, It is necessary to perform resynchronization, and communication cannot be performed until synchronization is achieved. Particularly when the synchronization period is long, there is a disadvantage that it takes a long time to perform communication.

SUMMARY OF THE INVENTION An object of the present invention is to provide a time division electronic switching device that does not require system resynchronization even when terminals are connected.

[Means to solve the problem]

The time division electronic switching device of the present invention is connected to each channel of a time division switch and can be connected to a plurality of synchronization signal transmission circuits that transmit the frame number of each frame, and the synchronization signal transmission circuit and the time division switch system. It has a terminal interface circuit that can connect the terminal and the time division switch in synchronization with the output from the synchronization signal sending circuit.

[For production]

By connecting each terminal interface circuit to a synchronization signal sending device for a specific channel using a time division switch, and by monitoring the frame number of each terminal interface circuit, system-synchronized communication can be performed between terminals. Thereafter, even if the connection of the terminals is changed, synchronization will not occur because the system is synchronized.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the time division electronic switching device of the present invention, and FIG. 2 is a diagram showing the frame structure of the time division switch 2. As shown in FIG.

The time division electronic switching device 1 includes a time division switch 2 and synchronization signal sending circuits 101 to 1 connected to the time division switch 2.
0o and terminal interface circuits 20-22. Terminals 40-42 are connected to terminal interface circuits 20-22, respectively.

In this embodiment, the time division switch 2 has a configuration of 8 bits per channel, and is capable of switching 1024 channels. Also, one frame is 8 Kbps with 1024 channels.
It is assumed that frame synchronization is achieved.

With the above configuration, it is not possible to distinguish between frames in Figure 2 (1), so there is no way to synchronize to perform data communication at 8 bps or less, and the only way is to synchronize between terminals. There is no. Therefore, as in this embodiment, the specific channel of the time division switch 2, in this embodiment “
When the synchronization signal sending circuit 10 is connected to the 0” channel,
In the synchronization signal sending circuit 101, for the “0” channel,
The 8-bit count value is sent out from "0" to "n" while incrementing it by 1 for each frame. Next to “n” is “0”
It shall be resumed from. FIG. 2(2) shows a multiplexed structure of 1024 channels, and FIG. 2(3) shows a frame structure of an 8-bit count value of a "0" channel.

With the above configuration, the frame number can be determined by monitoring the count value of the "0" channel, and the frames can be assigned numbers from "0" to "n" as shown in (4) in Figure 2. can be used to distinguish between frames.

In the terminal interface circuits 20 to 22, 31 in FIG.
．． By connecting 32 and 33 with the time division switch 2, the "0" channel can be monitored, that is, the frame number can be monitored. Therefore, in the communication between the terminals 40 and 41 via the terminal interface circuits 20 and 22, the connections 34 and 35 can perform communication with system synchronization even at a speed of 8 Kbps or less. In this example,
−K b ps.

Next, considering the case where the terminal 41 disconnects communication with the terminal 40 and starts communication with the terminal 42, since the terminal interface circuits 21 and 22 are system synchronized, the terminals 41 and 42 36. When the connection in 37 is made, synchronization loss occurs in all synchronization signal sending circuits 102 to 10.
In n, by fixedly reserving other channels of one frame and preparing a signal with a different period as a synchronization signal, it is possible to set the period of the synchronization signal to any desired period, not just bps. , and can support terminals with multiple synchronous speeds.

[Effects of the Invention] As explained above, the present invention connects a plurality of synchronization signal transmission circuits to each channel of a time division switch, and uses a terminal interface circuit to connect the synchronization signal transmission circuits connected via the time division switch system. By connecting terminals and time division switches in synchronization with the synchronization signal of This has the effect of eliminating the communication failure time during the synchronization loss period, and because it can accommodate a plurality of synchronization signal sending circuits, it has the effect of being able to support all types of synchronization speeds required as a system.

FIG. 1 is a block diagram showing an embodiment of the time division electronic switching device of the present invention, and FIG. 2 is a diagram showing the frame structure of the time division switch 2. As shown in FIG.

1... Time division electronic exchange device, 2... Time division switch, 10□~10. ...Synchronization signal sending circuit, 20-22.
...Terminal interface circuit, 31-37... Connection line, 40-42... Terminal.

Claims (1)

[Claims] 1. In a time division electronic switching device, a plurality of synchronization signal transmission circuits connected to a specific channel of a time division switch and transmitting frame numbers of each frame; and the synchronization signal transmission circuit and the time division switch system. 1. A time division electronic switching device characterized by having a terminal interface circuit capable of connecting a terminal and a time division switch in synchronization with an output from a synchronization signal sending circuit.