JPS6214972B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer method in a wireless parent-child telephone system, etc., in which a repeater is connected to an existing line and a plurality of handsets are connected via a wireless link. The purpose of the present invention is to provide stability and prevent interference to the destination handset by transmitting a paging signal to the destination handset after the off-hook signal of the calling side handset disappears when transferring to another handset.

Conventionally, in systems using a plurality of handsets of this type, the main method is to use a separate carrier for the radio link of each handset. However, in the system using multiple carriers, one telephone line should normally only be answered by one handset, but since multiple carriers are used, it is unreasonable and uneconomical.

The present invention focuses on this point and provides a system that can operate stably even in systems connected by wireless links using the same carrier.

Embodiments of the present invention will be described below with reference to the drawings. The drawing shows the configuration of a repeater, and in the drawing, 1 is a line connection circuit, 2 is a switch, 3 is a transmitter, 4 is a receiver, 5 is an antenna duplexer, and 6 is an antenna. Reference numeral 7 designates a control circuit, which includes a signal detection circuit 11 for identifying an off-hook signal of the handset detected via the receiver 4, a switch circuit 12 for driving a call signal by squelch, a busy signal generation circuit 13, and a selection of a call signal. It is composed of a circuit 14 and a calling signal generation circuit 15.

Next, the operation of the control circuit 7 will be explained. First, assume that any one handset goes off-hook while the line is not in use. Then, an off-hook signal is transmitted from the handset, and this off-hook signal is received by the receiver 4, which turns on the busy output of the signal detection circuit 11, activates the hook switch 2, and activates the line closing circuit 1. The line is closed. At the same time, the busy signal generation circuit 13 operates as a busy indication to other sets.
A busy signal is sent via the transmitter 3. In this state, since the receiver 4 is operating, the squelch circuit in the receiver 4 is operated, and this output turns off the switch circuit 12, so that the call signal generation circuit 15 does not output a call signal.

Next, when the handset in use transmits a transfer signal to perform a transfer operation to another handset, the signal detection circuit 11 detects the transfer signal and outputs a signal indicating this. The calling signal selection circuit 14 is set by this output. In this state, since the transfer signal is being sent from the transfer source handset, the switch circuit 12 is kept OFF due to the squelch output in the receiver 4, and the ringing signal is not sent, so transfer cannot be performed. When the transfer source handset goes on-hook, the squelch output in the receiver 4 is
OFF, operating the switch circuit 12,
A transfer destination is selected by the paging signal selection circuit 14, and the paging signal generation circuit 1 is selected for the transfer destination handset.
5 sends out a calling signal.

Thereafter, when all the handsets are in the on-hook state after performing the busy → transfer → busy operation according to the same procedure, the signal detection circuit 11 resets the ringing signal selection circuit 14 and switches the hook switch 2.
Turn off and enter standby mode. At this time, the squelch output in the receiver 4 is OFF, the switch circuit 12 indicates an operating state, but the calling signal selection circuit 14 is in a reset state, and the transmitter 3 has stopped transmitting due to an on-hook state. No signal is sent.

As described above, in the wireless telephone transfer system according to the present invention, after a transfer signal is transmitted from a handset during a call, disappearance of the off-hook signal of the handset is detected, that is, on-hook is detected, and the transfer destination handset is called. Since signals are generated, two handsets cannot be linked at the same time, so the wireless link only needs to use a single frequency, and from a control point of view, it is extremely stable as it depends on the presence or absence of signals. . Furthermore, as a result, an inexpensive and stable transfer method can be provided, which has great practical merits.

[Brief explanation of the drawing]

The figure is a block diagram of a repeater to which the wireless telephone transfer system according to the present invention is applied. 11...signal detection circuit, 15...calling signal generation circuit.

Claims (1)

[Claims] 1. When a plurality of handsets are connected via a radio link through a repeater connected to a telephone line, and the off-hook signal from a certain handset disappears following the arrival of a transfer signal from a certain handset, the ringing signal generation circuit A wireless telephone transfer method characterized by activating the transfer destination handset and calling the transfer destination handset.