JPS63161737A - Cordless telephone set by multi-channel access system - Google Patents

Abstract

PURPOSE:To attain talking between slave sets by allowing a control section of a master set to use a modulation circuit to modulate a signal demodulated by a demodulation circuit and sending the result to other slave set in an outgoing frequency when the master set receives a signal from a calling slave set to other slave set in the incoming frequency. CONSTITUTION:A transmission signal from a microphone 11 of a slave set 1 is amplified by an amplifier 12 and radiated as a radio wave from an antenna 18 in an incoming frequency via a modulation circuit 16 and a transmission section 17. The radio wave received by the master set 4 is demodulated by a demodulation circuit 49 via an antenna 51 and a reception section 50, modulated by a modulation circuit 43 and radiated as a radio wave in an outgoing frequency from an antenna 41 via a transmission section 42. The radio wave is received by an antenna 19 of the slave set 2 and demodulated by a demodulation circuit 21 via a reception section 20, amplified by an amplifier circuit 22 and outputted as a sound from a speaker 23. Thus, the transmission from the slave set 1 to the slave set 2 is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cordless telephone with multi-channel access system.

(Prior art) The frequency fd transmitted from the base unit to each slave unit is the same,
In addition, in a cordless telephone in which the frequency fu transmitted from each handset to the base unit is the same, there has been no device that allows handsets to communicate with each other.

(Problem to be solved by the invention) Therefore, in order to talk between handsets, it is sufficient to change the transmission frequency fu of one handset to the above frequency fd, but this makes the device complicated and in practice. It was something that could not be made into a product.

(Means for Solving the Problems) The present invention solves the above-mentioned drawbacks, and the configuration thereof is shown below.

It is composed of a base unit and multiple slave units, and is a multi-channel system in which transmission from the base unit to multiple slave units is on the same downlink frequency FD, and from multiple slave units to the base unit on the same uplink frequency FU. In an access type cordless telephone, when a base unit receives a signal from a calling handset to another handset at an uplink frequency fu, the control unit of the base unit modulates the signal demodulated by a demodulation circuit using a modulation circuit and transmits the signal to another handset. Cordless telephone with multi-channel access method that transmits to other handsets on frequency FD.

(Example) FIG. 1 is a system diagram of a cordless telephone.

1.2. 4 is a slave unit, 4 is a base unit, and 5 is a telephone line.

47 is a telephone circuit consisting of a dial telephone circuit, etc.;
8 is a handset.

fu indicates the upstream frequency (transmission frequency from the slave unit to the base unit) of all the control channels and communication channels, and fd represents the downlink frequency (transmission frequency from the base unit to the slave unit) of all the control channels and the communication channel.

fcu is the uplink frequency of the control channel, fcd is the downlink frequency of the control channel, fsu is the uplink frequency of the communication channel, and fsd is the downlink frequency of the communication channel.

Note that since the configuration of the handset 2 is the same as that of the handset 1, illustration of the internal mechanism is omitted.

The operation of calling handset 2 from handset 1 and making a call will be described below.

When the base unit is on standby, the control unit 46 controls the frequency synthesizer 44 to receive and monitor the upstream frequency fcu of the control channel. When the handset is in standby, the control unit 14 controls the frequency synthesizer 15 to set the downlink frequency fcd of the control channel.
The reception is monitored.

First, child call data for calling the child device 2 is sent from the child device 1 to the parent device 4. That is, when the operation section 13 is operated, the control section 14 controls the frequency synthesizer 15 and also controls the ID.
The data and child call data are converted into analog signals for MSK modulation, further modulated by the modulation circuit 16, and transmitted by the transmitter 1.
The control channel is emitted from the antenna 18 as a radio wave at the upstream frequency fcu via the control channel 7.

Base device 4 receives the radio wave through antenna 51 and receiving section 50 and demodulates it through demodulation circuit 49 which receives the output from frequency synthesizer 44 . Furthermore, the control unit 46 converts the analog signal into a digital signal, and further converts the sent ID into a digital signal.
After collating the data and analyzing the child call data,
When the controller 46 confirms that it is its own handset ID, the controller 46
After confirming that the ID data and the designated call channel data are already available, the designated call channel data is converted into an analog signal for MSK modulation, further modulated by a modulation circuit 43 that receives the output of a frequency synthesizer 44, and controlled via a transmitter 42. It is emitted as a radio wave from the antenna 41 at the downlink frequency fed of the channel.

In the handset 2, the transmitted radio waves are received by the antenna 19 and the receiving section 20, demodulated by the demodulation circuit 21, and taken into the control section 14. The control unit 14 converts the demodulated analog signal into digital signals such as ID data, designated call channel data, and reference pulses. When the control unit 14 identifies that the ID data is its own, the ID data and acknowledgment data are MSK modulated and sent out at the upstream frequency fcu of the control channel after a predetermined time t2 after detecting the reference pulse P. do. Subsequently, the control unit 14 controls the frequency synthesizer 15
to enable transmission and reception on the specified call channel.

Further, in the handset 1, the transmitted radio waves are received by the antenna 19 and the receiving section 20, demodulated by the demodulation circuit 21, and taken into the control section 14. The control unit 14 converts the demodulated analog signal into digital signals such as ID data, designated call channel data, and reference pulses. After the control unit 14 detects the reference pulse P, after a predetermined time t1, ID data and acknowledgment data are MSK modulated and sent at the upstream frequency fcu of the control channel, and then the control unit 14 converts the frequency synthesizer 15 so that the designated communication channel can be transmitted and received.

FIG. 2 shows the timing at which the handset responds on the control channel.

When the base unit 4 receives the acknowledgment data from the slave unit 1.2, its control unit 46 controls the frequency synthesizer 44 to enable transmission and reception of the designated communication channel. Furthermore, the slave ringing sound data is sent to the slave unit via the communication channel.

When the handset 2 receives the child ringing sound data on the communication channel, it generates a ringing sound under the control of the control unit 14. When the called party hears the ringing tone and performs a response operation, the handset 2 sends response data to the base unit 4 through the communication channel.

In the base unit 4, the control unit 46 switches the switching path 45 after confirming the response data.

At this point, communication between handset 1 and handset 2 becomes possible.

That is, the transmission signal from the microphone 11 of the handset 1 is amplified by the amplifier 12, modulated by the modulation circuit 16 in response to the output of the frequency synthesizer 15, transmitted through the transmitter 17, and sent from the antenna 18 to the upstream frequency fsu of the communication channel. is emitted as radio waves. The radio waves received by the base unit 4 pass through the antenna 51 and the receiving section 50 and are demodulated by the demodulation circuit 49. Furthermore, since the switching circuit 45 is switched, the demodulated audio signal is received and modulated by the output of the frequency synthesizer 44 in the modulation circuit 43, and transmitted as a radio wave from the antenna 41 via the transmitter 42 at the lower frequency fsd of the communication channel. be done.

This radio wave is received by the antenna 19 of the handset 2, and the receiving unit 2
0, the signal is demodulated by the demodulation circuit 21 which receives the output of the frequency synthesizer 15, and becomes an audio signal.

The signal is further amplified by the amplifier circuit 22 and output as sound from the speaker 23. Therefore, a transmission operation is performed from handset 1 to handset 2. The operation of transmitting a call from the handset 2 to the handset 1 is the same as that described above, and will therefore be omitted.

It is also possible to send and receive data instead of audio signals.

Transmission using the communication channel up frequency fsu from the handset 1 is simultaneously received by the handset 1 at the communication channel down frequency fsd via the base unit 4, but the reception level is controlled to be lowered while transmitting. If you do this, there will be no problem with your phone calls. Further, if the handset 1 and handset 2 transmit data simultaneously, interference, suppression, interference, etc. will occur in the reception section of the base unit 4, making it impossible to receive signals normally. Therefore, calls in the call channels are actually carried out alternately.

Note that in the above-described embodiment, various data are once converted into analog signals in order to perform MSK conversion, but the data may be FSK-modulated and transmitted without performing this conversion.

Further, in the above-described embodiment, the case where there are two handsets and the same -rD is described, but the present invention is not limited to this.

(Effects of the Invention) The present invention enables economical communication between handsets with a simple configuration in a multi-channel access type cordless telephone consisting of a base unit and a plurality of handsets.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a cordless telephone that is an embodiment of the present invention. FIG. 2 is a response timing chart of the handset. 1.2...Slave unit, 4...Main unit, 5...
····telephone line. Patent applicant Representative applicant Kanda Tsushin Kogyo Co., Ltd. Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] It is composed of a base unit and multiple slave units, and is a multi-channel system in which transmission from the base unit to multiple slave units is on the same downlink frequency FD, and from multiple slave units to the base unit on the same uplink frequency FU. In an access type cordless telephone, when a base unit receives a signal from a calling handset to another handset at an uplink frequency fu, the control unit of the base unit modulates the signal demodulated by a demodulation circuit using a modulation circuit and transmits the signal to another handset. A multi-channel access type cordless telephone characterized by transmitting data to other handsets at frequency FD.