JPH0223102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a meeting line used for maintenance of time division multiple access (TDMA).

[Description of prior art]

In the time division multiple access system, the meeting line may be transmitted in the multiplexed signal, or a separate line dedicated to the meeting line may be provided. When transmitting multiplexed signals, a special signal system different from that of general telephone lines is used for transmission. However, transmitting a meeting line in a multiplexed signal reduces the number of general communication lines, and the special signaling system also causes interference noise.

Further, if a meeting line is provided separately from the multiplex signal, there is an advantage that it can be used even when the multiplex line is damaged, but the equipment becomes larger.

[Purpose of the invention]

The present invention is a method for transmitting a meeting line in a multiplexed signal, in which a predetermined line among the general call lines is separated from the general call line only when the meeting line is needed, and the signal system is exactly the same as that for general calls. The purpose is to provide a system that can be used as a meeting line.

[Features of the invention]

According to the present invention, in a time division multiple access system, a master station has means for blocking a general communication line and occupying a predetermined communication time slot as a meeting line as necessary. The control time slot is also used to indicate whether or not the call time slot is occupied and available for use as a meeting line. On the other hand, the slave station receives the signal from the control time slot and has means for determining whether or not the meeting line is usable, and has means for switching the telephone line to the meeting line as necessary.

Due to the above features, a line for general calls and a meeting line can be shared without using any special signaling system, and an economical meeting line can therefore be constructed.

That is, it includes one master station and a plurality of slave stations connected to the master station via wireless lines, and the master station has a large number of communication line control circuits each connected to a large number of general communication lines, A plurality of time slot control circuits connected to the radio line, a switch network interconnecting the time slot control circuits and the communication line control circuit, and a central control unit controlling the switch network, In a time division multiple access system, each slave station is equipped with a slave station control unit that detects a time slot assigned to the slave station in the wireless line and inputs/outputs information to that time slot. comprises a meeting line control unit to which a meeting line is connected and connected to the switch network, and means for transmitting and receiving a meeting line control signal to the control time slot of the radio line according to a command from the central control, The unit includes a control means for connecting the meeting line control unit to one of the time slot control circuits, and the slave station control unit of the slave station includes means for identifying the meeting line control signal of the control time slot. The mobile station is characterized in that the slave station is provided with a switch that switches and connects the input/output line of the slave station control section to the meeting line based on the output of the identifying means.

[Explanation based on examples]

FIG. 1 is a conceptual diagram of a time division multiple access system.
FIG. 2 is a block configuration diagram according to an embodiment of the present invention. In FIGS. 1 and 2, A is a master station, B is a slave station, and they are scattered around the master station A.

At master station A, n general communication lines 1, 2, 3
are connected to communication line control circuits 4, 5, and 6, respectively, and undergo two-wire and four-wire conversion and level conversion. One input/output line passes through a switch network 7 and is connected to time slot control circuits 8, 9, and 10.
The other input/output line is connected to input a control signal from the central control unit 11. Further, the input terminal of the central control unit 11 is connected to the switch 12, and the output terminal is connected to the above-mentioned communication line control circuits 4, 5, 6.
, the switch network 7, the time slot control circuits 8, 9, 10, and the control time slot control circuit 13, respectively.

The feature of the present invention is that the meeting call line 14 is connected to the switch network 7 through a meeting line control circuit 15. The outputs of the time slot control circuits 8, 9, 10 and 13 are connected as radio wave signals to the slave station via the radio 13 using one time slot to form a telephone line. At the slave station B, the radio 17 passes through the slave station control unit 1 and is connected to the general telephone line 20 by the switch 19.
and a meeting line 21 for distribution. The switch 19 is connected to control the output of the slave station control section 18 and the signal from the switch 22 through a gate 23.

Next, to explain the operation of the apparatus according to the embodiment of the present invention, when the meeting line is not used, the general communication lines 1, 2, and 3 that are used for communication are the communication line control circuits 4, 5, and 3. 6, the time slot control circuits 8, 9, 10 are connected via the switch network 7.
connected to one of them. The time slot control circuit is determined by the control of the central control section. Then, using one time slot, a communication line is formed with the slave station via the radio device 16 as a radio wave signal.

Similarly, in the slave station, among the data strings transmitted and received via the radio device 17, the call time slot number determined by the central control unit 11 of the master station is used for control transmitted from the control time slot control circuit 13. The designated time slot is transmitted to the slave station control unit 18, and the data of the designated time slot is transmitted and received to form a communication line with the master station.

On the other hand, when using a meeting line, a channel normally used as a general call line is assigned for the meeting line. That is, when the switch 12 is pressed at the master station, the central control section 11 controls one of the time slot control circuits 8, 9, and 10 (i).
The meeting line control circuit 15 is connected via the switch network 7.
Connect with. It also informs the control time slot control circuit 13 that the meeting line is now usable at time slot i, and transmits this to the slave station using the control time slot. If the slave station B is not in the middle of a call in this state, the gate 23 is opened and a display is sent from the slave station control section 18 to the operator. When switch 22 is pressed, switch 19 operates,
A telephone line to the slave station control section 18 is connected to a meeting line 21. Also, if the slave station is talking, Gate 2
3 is closed, and even if the switch 22 is pressed, the telephone line is connected to the general telephone line 20 side.

If all of the time slot control circuits 8, 9, and 10 are in use and the meeting line control circuit 15 cannot be connected, it is indicated that the meeting line time slot is prohibited from use.

In this way, even if the switch 12 on the master station side is pressed, if all of the time slot control circuits 8, 9, and 10 are used for general calls, the call goes into a "waiting" state, and a call line for a meeting line is not formed. However, if any one of the time slot control circuits 8, 9, and 10 is open, the meeting line becomes usable, and the time slot is blocked for general calls until the switch 12 is released.

On the other hand, when using the meeting line from the slave station side, when the switch 22 is pressed, the slave station control section 18 sends a command to the master station via the radio 17 using a control time slot signal. The master station detects the control time slot 13 and sends out a display from the central control section 11. As a result, when the switch 12 is operated, the switch network 7 is controlled to form a meeting line.

Generally, time slot control circuits 8, 9, 10
A sufficient number of lines can be prepared so that call processing will not be affected even if one line is blocked for a meeting except during the busiest call times.

Also, during general calls, the number of call line control circuits 4, 5, and 6 and the number of slave stations correspond one-to-one, and they have the same ID.
If you have a code and the code is different, a call line will not be formed, but if it is a meeting line, switch 22
All slave stations for which is pressed can use the time slot of the meeting line.

〔Effect of the invention〕

As described above, according to the present invention, by occupying one of the time slots for general calls for a meeting line as necessary, there is no waste in lines.
Furthermore, since no special signaling system is used, there is no interference with other communication lines. In this way, an economical meeting line can be obtained by sharing the line for general calls.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a time division multiple access system. FIG. 2 is a block diagram of an embodiment of the present invention. A... Master station, Bi... One of multiple slave stations, 1,
2, 3... General call line, 4, 5, 6... Call line control circuit, 7... Switch network, 8, 9, 10...
Time slot control circuit, 11... central control section,
12... Meeting line instruction switch, 13... Control time slot control circuit, 14... Meeting line, 15... Meeting line control circuit, 16, 17...
... Radio equipment, 18 ... Slave station control unit, 19 ... Changeover switch, 20 ... General call line, 21 ... Meeting line, 22 ... Meeting line display switch, 23
……Gate.

Claims (1)

[Claims] 1. Includes one master station and a plurality of slave stations connected to the master station via wireless lines, and the master station has a number of telephone lines each connected to a number of general telephone lines. A line control circuit, a plurality of time slot control circuits connected to the radio line, a switch network that interconnects the time slot control circuit and the call line control circuit, and a central control unit that controls the switch network. In a time division multiple access system, the slave station is provided with a slave station control unit that detects a time slot assigned to the slave station in the wireless line and inputs and outputs information to the time slot. The master station includes a meeting line control unit to which a meeting line is connected and connected to the switch network, and means for transmitting and receiving a meeting line control signal to the control time slot of the radio line according to instructions from the central control unit. The central control unit includes control means for connecting the meeting line control unit to one of the time slot control circuits, and the slave station control unit of the slave station connects the meeting line control unit to one of the time slot control circuits. A time division multiple access device comprising means for identifying a signal, and the slave station is equipped with a switch that switches and connects the input/output line of the slave station control unit to a meeting line based on the output of the identifying means. Method meeting line method.