SU788431A1 - Device for indication of the number of calling subscriber on the telephone set of called subscriber - Google Patents

Description

through the memory unit to the inputs of the display unit.

The drawing shows a structural electrical circuit of the proposed device.

The device for indicating the caller's number on the telephone of the called subscriber, contains at the automatic telephone exchange 1 control and switching unit 2, subscriber set 3, automatic number determining unit 4, register 5, request unit 6, switching unit 7, conversion and transmission unit 8 filter 9, the first and second switches 10, 11, respectively, on the subscriber side 12 filter block 13, code decoder 14, And 15 element, converter 16, distributor 17, memory block 18, display unit 19, with ATC link on a subscriber side subscriber line 20.

The device works as follows.

The coded signals entering the control unit 2 in the commutation determining the number of the called subscriber (for example, pulses from the dialer) are received in parallel and recorded in register 5. Thereafter, a signal is sent to the request block 6 from the output of register 5. The block b sends a request on the path connected to the caller to the path in block 4 of the automatic number identification (AON). In the latter case, in the particular case, the AON equipment can be used to transmit the caller's number to the AMTS to record the cost of the call. The coded signals defining the caller's f-number, transmitted by block 4 included in the caller's subscriber set 3, are received and recorded in register 5. Register 5 transmits the number to switch block 7. The latter determines the required subscriber line 20 and, by controlling the switch 10, switches it to subscriber set 3 via switch 10 and filter 9. Then register 5 transfers the number j8 to conversion and transmission block 8. Unit 8 generates and sends through the contact of the switch 10 the first special code combination with the frequency code “2 out of 6 B to the subscriber line 20, then the code combinations corresponding to the digits of the p number, and the second special code combination.

The ti {b frequencies used for coding in block 8 should lie in the frequency band of the talked spectrum (0.3-3.4 kHz) for their transmission over compressed subscriber lines. In this case, if the called subscriber is engaged in a conversation with another the subscriber, to the latter should not get the signals transmitted by block 8. For this is the filter 9. In particular.

frequencies, -E can be taken in the range 2.7-3.4 kHz, then filter 9 must suppress the frequencies of this range. At the same time, the subscribers practically do not feel any deterioration in the transmission quality, especially since the transmission time of a block of 8 coded digits, according to available estimates, does not exceed 1 s.

Upon completion of the transfer of all combinations, unit 8 sends a signal to switching unit 7, which returns the contact of switch 10 to the initial state.

Block 13 contains filters that are tuned to the corresponding frequencies f, -f, transmitted by block 8. The signals allocated by block 13 are fed to the inputs of the decoder 14 and the And 15 element. Decipher 14, selecting the first special code combination, sends a signal to the block The 18 memories for erasing (or shifting, if the memory block 18 can store several numbers) of the previous J5 number and at the same time deliver the enabling signal to the second input of the And 15 element. As a result, the following code combinations defining the digits of the number j come through first entry ele And 15 to the converter 16. The latter, based on the received code combinations, at its output generates impulse signals that allow to produce zat. Write the corresponding digits of the number f to memory block 18 and then highlight them in display block 19. These signals from the output of the converter 16 are fed to the distributor 17, which provides the recording of the next digit of the number p to the corresponding cell of the memory block 18 and flashing it at a certain position of the display unit 19.

5 Upon Receiving the second special code combination, the decoder 14 removes the enabling signal from the input element And 15.

Claims (1)

1. Ivanova O. N. Automatic switching systems. M., “Svy, 1978. with. 387 (prototype).