JPH06338852A - Digital cordless telephone system - Google Patents

Abstract

PURPOSE:To excellently perform the calling of the call between slave equipments with little power consumption by transmitting a connection request signal to the slave equipment on the side of an incoming call via a master equipment ans by making each slave equipment a reception state. CONSTITUTION:In the communication control part 14 of a slave equipment, a reception operation is controlled so as to receive only control signals transmitted by a prescribed control channel from a master equipment by a prescribed interval when the part 14 becomes a reception standby state. When the contents of the received control signal is discriminated and it is judged that this slave equipment is called by the connection request signal included in the control signal, this slave equipment is made to perform the pertinent operation. When each slave equipment is called by this connection request signal, there are a case where a communication is performed between master equipments because of an extension call or a line wire call and a case where the communication is performed between other slave equipments because of the extension call. When an originating call is to be performed from each slave equipment because of the line wire call or the extension call, the connection request signal is transmitted to the master equipment by using the control channel. As a result, the time when the reception operation is performed in the reception standby state is extremely shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone device in which communication between a base unit and a handset is performed by transmitting / receiving digital data.

[0002]

2. Description of the Related Art A digital cordless telephone system is constructed, for example, as shown in FIG. In FIG. 6, reference numeral 1 denotes a base unit serving as a base station, and the base unit 1 is connected to a telephone line and includes an antenna 1a for communicating with a handset. A plurality of (three in this case) slaves capable of communicating with the master 1 are prepared. That is, the slaves 2, 3 and 4 are prepared, the antennas 2a, 3a and 4a are attached to the slaves 2, 3 and 4, respectively, and the antenna 1a of the master 1 and the antennas of the slaves 2, 3 and 4 are attached. 2a, 3a, 4
Wireless transmission is performed with a.

When a call is made with each of the slave units 2, 3 and 4 to the master unit 1 (or the other party connected to the master unit 1 via a telephone line), a connection control signal of a predetermined format is transmitted to the master unit 1.
Then, the voice data converted into digital data is transmitted to the base unit 1 in a time division manner with the base unit 1 to make a call.

In such a digital cordless telephone device, transmission and reception are performed at the same frequency, and so-called ping-pong transmission is performed in a TDD system (time division duplex system) or a TDMA / TDD system (time division multiple access / time division). There are some that are adopted.

That is, in the case of the TDD system, for example, A in FIG.
, One channel (frequency) is temporally divided into a transmission slot T and a reception slot R, these slots T and R are alternately repeated, and a guard is provided between these slots T and R. A time (not shown) is provided. In this case, for example, each slot T and R is set to 1 msec and the guard time is set to several tens of microseconds. And
The mobile phone (slave unit) communicates with the base station (parent device) in the transmission slot T and receives from the base station in the reception slot R.

In the case of the TDMA / TDD system,
As shown in FIG. 7B, the transmission slot T and the reception slot R in one channel are used in the communication between one slave unit and the master unit.
, Are used only once every several cycles, and other transmission slots T and reception slots R in the same channel are used for communication between another slave unit and the master unit, and a plurality of units are used for one channel. It is multiplexed so that communication between communication devices can be performed.

By being multiplexed in this way, the frequency band prepared for the cordless telephone can be used efficiently. By the way, in the case of performing such communication, the transmission of the control signal from the master unit to each slave unit is performed according to a fixed format every predetermined period. That is, for example, as shown in FIG. 8A, the control signal d1 is transmitted to each slave unit for 625 μs every 125 msec. Then, for example, when any one of the slave units is called by an extension call from the master unit, the individual number of the corresponding slave unit is transmitted by the control signal d1 and the corresponding slave unit is called. Then, when each of the slave units is in the reception standby state, if only this control signal is intermittently received at a predetermined cycle (for example, once every 1.2 seconds), the reception standby state is increased. It is possible to reduce the power consumption required to receive the. It should be noted that the control signal may be received once for 625 μ seconds in principle, but in actuality, in consideration of the rising time of the receiving unit, the control signal is received only for about 10 m seconds at a time. Therefore, 1.
If the reception is performed every 10 seconds for every 2 seconds, the time during which the receiving unit is operating becomes 1/120, and the power consumption can be significantly reduced compared to the case where the reception is performed continuously.

[0008]

However, in actuality, each slave unit of such a digital cordless telephone device not only answers the call from the master unit but also makes an extension call between the slave units. Therefore, it is necessary to scan whether or not there is a call from each handset on the inter-handset communication channel. In this case, if, for example, 10 waves (that is, 10 channels) are prepared as a channel for inter-slave communication, it is necessary to scan all 10 channels at a predetermined cycle. Therefore, as shown in FIG. 8B, for example, as shown in B of FIG. 8, the period during which the power of the reception unit is turned on when each slave unit is in the reception standby state is 120 msec including 625 μsec in which the control signal d1 is transmitted from the master unit. Then, it is necessary to sequentially scan 10 channels in a period t1 (about 110 msec) after receiving the control signal d1 from the master unit to determine whether or not there is a call from any slave unit. It should be noted that here, time t for scanning 10 channels
1 is set to about 110 msec because it takes about 10 msec to scan one wave and about 1 msec to switch channels.

Scanning all the communication channels between the handset units in this way has the disadvantage that it takes time. For example, if the receiving unit is turned on for 120 msec at a cycle of 1.2 sec, then a period of 1/10 Since the power is turned on, the power consumption in the reception standby state is significantly increased as compared with the case where the communication channel between the handset units is not scanned.

In view of the above point, the present invention is to enable a cordless telephone device of this type to call a telephone call between handset units favorably with low power consumption.

[0011]

DISCLOSURE OF THE INVENTION The present invention relates to a digital cordless telephone apparatus which comprises a master unit and a plurality of slave units, and makes a call by differently transmitting and receiving digital data in time. When a call is made between machines, a connection request signal is transmitted from the calling side child machine to the parent machine, and when this connection request signal is received by the parent machine, the parent machine connects to the corresponding called party child machine. A request signal is transmitted, and when the connection request signal is received by the called-side handset, a call between the calling-side handset and the called-side handset is started. Is.

Further, in this case, the called side child device performs the receiving operation only during the period when the control signal including the connection request signal is transmitted from the parent device.

[0013]

According to the present invention, the connection request signal is transmitted to the called-side child device via the parent device, so that the called-side child device only receives the control signal from the parent device. Then, it is understood that the call between the handset units will be received, and it is not necessary to receive a signal from another handset unit.

In this case, the operating time of each slave unit in the reception standby state can be minimized by setting each slave unit in the receiving state only at the timing when the control signal is transmitted from the master unit.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

This example is applied to a TDD type digital cordless telephone device as in the conventional example, and its slave unit is constructed as shown in FIG. That is, in FIG. 1, reference numeral 11 denotes an antenna, and the radio unit 12 receives and processes data received from the master unit or another slave unit by the antenna 11, and supplies the data to the modulation / demodulation unit 13 to demodulate the received data. Then, the demodulated received data is sent to A via the communication control unit 14.
AD obtained by receiving and receiving the DPCM codec section 15
The PCM digital data is used as an analog audio signal, and this analog audio signal is output from the speaker 16.

The audio signal picked up by the microphone 17 is AD
It is supplied to the PCM codec section 15 to be ADPCM digital data, and this digital data is sent to the communication control section 14
The data is supplied to the modulation / demodulation unit 13 via the wireless LAN and modulated for transmission, and the modulated data is wirelessly transmitted from the antenna 11 connected to the wireless unit 12.

Further, the key input section 18 is connected to the ADPCM codec section 1 via the man-machine interface section 19.
5, and the operation information of the key input unit 18 is supplied to the communication control unit 14 side. Further, the display unit 20 is connected to the man-machine interface unit 19 so that the operating state and the like are displayed.

Then, the communication control section 14 controls the receiving operation so as to receive only the control signal transmitted from the master unit on a predetermined control channel at a predetermined interval when in the reception standby state. is there. Then, the content of the received control signal is determined, and when it is determined that the slave unit is called by the connection request signal included in the control signal, the slave unit is caused to perform the corresponding operation. When each cordless handset is called by this connection request signal, it communicates with the base unit for internal or external telephone calls, and communicates with other cordless handsets for internal telephone calls. There are cases when In addition, when you want to make a call from each cordless handset for an external call or an extension call (extension call with the base unit and call between the handset), use the control channel to send a connection request signal to the base unit. I am sending it.

Next, the configuration of the master unit is shown in FIG. 2. As in the case of the slave unit, the data received from the slave unit by the antenna 31 is received by the radio unit 32, processed by the radio unit 32, and supplied to the modem unit 33. Demodulate the data. Then, the demodulated received data is supplied to the ADPCM codec section 35 via the communication control section 34, the ADPCM digital data obtained by reception is used as an analog audio signal, and this analog audio signal is supplied to the line interface section 36. , To the analog telephone line connection terminal 37 side.

Further, an analog voice signal obtained from the analog telephone line connection terminal 37 side is supplied to the ADPCM codec unit 15 via the line interface unit 36, and A
The DPCM digital data is supplied to the modulation / demodulation unit 33 via the communication control unit 34 to be modulated for transmission, and the modulated data is wirelessly transmitted from the antenna 31 connected to the wireless unit 32.

Further, the handset 38 is directly connected to the line interface unit 36 so that the telephone can be communicated with the outside line side through the analog telephone line connection terminal 37, and the handset 38 can be connected to the ADPCM codec unit 15 side so that a child can be connected. It is possible to make extension calls with the machine. Further, the key input unit 39 is connected to the line interface unit 36 so that various controls such as transmission to an outside line can be performed.

Then, in the communication control section 34 of this base unit,
A dedicated channel (frequency band) prepared for control signal transmission is used to transmit control signals at predetermined intervals, and this control signal is used to call other slave units. In the reception standby state, the communication control unit 3
At 4, it is detected whether or not the connection request signal for the inter-slave communication is transmitted from another slave. Then, when there is a request from the connection request signal that requires a call with the base unit, a control signal is used to instruct the applicable handset side to set the call channel, etc. Start communication. Also, when a call between slaves with another slave is requested by the connection request signal, control of the communication control unit 34 transmits a control signal to the called slave by using a control channel. Then, a connection request signal indicating that the call between the handset units is started is transmitted.

Next, the state in which the control signal is transmitted between the master unit and the slave unit having such a configuration will be described.
Transmission and reception in the master unit in the reception standby state are performed in the state shown in A of FIG. Ie, using the control channel 6
The timing of transmitting the control signal for 25 μs to each slave unit is indicated by the period in which the waveform of A in FIG. 3 rises. The transmission timing of this control signal is a cycle of 125 msec.

The control signal once for 625 μs is
It is configured as shown in FIG. That is, the preamble PR first follows a fixed pattern for a predetermined period, and in the following, a unique word UW of a specific pattern indicating a control signal, a channel type C for communication, a control data CAC indicating control content, an error detection parity. It is CRC.

Then, 2.5 msec after the transmission of the control signal from the master unit for 625 μsec (accurately after the transmission is started), the control channel data is transmitted for 625 μsec by the master unit. To receive. The timing of this reception is shown in the period when the waveform of A in FIG. 3 falls.

Further, in the calling side slave unit which wants to start an extension call, etc., as shown in FIG.
After receiving the control signal of the msec cycle (the falling period of B in FIG. 3) and 2.5 msec after the reception timing is used as a reference, the control channel is used to transmit the connection request signal for 625 μsec. (The rising period of B in FIG. 3).

Further, the slave unit that remains in the reception standby state (here, the slave unit on the called side) receives a control signal of a 125 msec cycle in N cycles (N is an arbitrary number) ( During the falling edge of C in FIG. 3), follow the instructions given by this control signal.

Next, FIG. 5 shows a connection sequence when an extension call is started by transmitting such a control signal.

First, when it is desired to start an extension call with a certain slave unit (hereinafter, this slave unit will be referred to as a calling side slave unit), the calling side slave unit scans a channel prepared for an extension call. Then, an empty channel and an empty slot are detected.
And if there are free channels and slots,
At the timing shown in B of FIG. 3, a connection request signal is transmitted to the master unit using the control channel (step 101). In this connection request signal, the data of the individual number of the called-side child device and the data of the detected free channel number and slot number are transmitted. Then, in the calling side handset, a call channel is set in an empty slot in the detected free channel, and the call signal of the called side handset is transmitted through this channel (step 1).
02).

When the master unit receives a connection request signal for inter-slave communication from the calling side slave unit, the control channel is used for the called side slave unit having the individual number indicated by the connection request signal. The connection request signal is transmitted by the transmission of the control signal of the above 125 msec cycle (step 103). In the connection request signal at this time, the data of the individual number of the called-side child device,
The detected empty channel and the data of the channel number of the empty slot are transmitted.

Upon reception of this connection request signal, the called-side slave unit sets the call channel to the channel number and slot number indicated by this connection request signal,
Using this call channel, a synchronization signal is transmitted to the calling handset (step 104). Then, when the calling side child device receives the synchronization signal, the calling side child device transmits the synchronization signal using the same communication channel (step 105). When the called-side child device receives the synchronization signal, the communication control unit 14 in the called-side child device causes the ringer to ring, and when the called-side child device goes off-hook (that is, someone calls When the handset responds), the response signal is transmitted on the set communication channel (step 106). When the calling handset receives this response signal, communication between the calling handset and the called handset using the set call channel is started, and an extension call is started. (Step 106).

As described above, according to the digital cordless telephone apparatus of the present example, as the operation until the extension call between the slave units is started, the calling side slave unit connects to the called side slave unit via the master unit. Since the request signal is transmitted, if the called-side slave unit receives only the connection request signal transmitted from the master unit, the extension call request between the slave units can be recognized and the direct call as in the past. Eliminates the need to scan the channel for each extension call. Therefore, in the reception standby state, the reception operation may be performed only at the timing when the control signal is transmitted from the master unit using the dedicated control channel.
The time during which the reception operation is performed in the reception standby state becomes very short. For example, if it is necessary to receive the control signal once for 10 msec, and to receive 10 msec for every 1.2 sec,
The operating time of the receiving unit is 1/120, and no matter how many communication channels are prepared, it is enough to perform only the receiving operation for 1/120. The same operation state as when not talking between handsets. Becomes Therefore, even with a cordless telephone device of a system capable of performing inter-slave communication, the power consumption in the reception standby state can be significantly reduced, and the duration of the battery built in each slave is extended. You can

[0034]

According to the present invention, the connection request signal is transmitted to the called-side child device through the parent device, so that the called-side child device receives the control signal from the parent device. Only by doing so, it is possible to know that a call between handset units will be received, and there is an effect that there is no need to receive signals from other handset units.

In this case, by setting each slave unit to the receiving state only at the timing when the control signal is transmitted from the master unit, the operating time of each slave unit in the reception standby state can be minimized,
Therefore, the duration of the battery built in the slave unit can be extended.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a child device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a base unit according to an embodiment.

FIG. 3 is a timing diagram for explaining one embodiment.

FIG. 4 is an explanatory diagram showing control signals according to an embodiment.

FIG. 5 is an explanatory diagram showing a connection sequence according to an embodiment.

FIG. 6 is a configuration diagram showing a system configuration of a cordless telephone device.

FIG. 7 is a configuration diagram showing a communication system.

FIG. 8 is a timing diagram showing a conventional transmission / reception state of control signals.

[Explanation of symbols]

 12, 32 Radio part 13, 33 Modulation / demodulation part 14, 34 Communication control part 15, 35 ADPCM codec part

Claims (2)

[Claims] 1. A digital cordless telephone device comprising a base unit and a plurality of handset units, wherein the transmission and the reception of digital data are temporally different from each other, and when a call is made between the respective handset units, When the caller-side slave unit transmits a connection request signal to the master unit and the master unit receives this connection request signal, the master unit transmits the connection request signal to the corresponding caller-side slave unit, and A digital cordless telephone device configured to start inter-slave communication between the calling-side slave and the called-side slave when the call-side slave receives a connection request signal. 2. The digital cordless telephone device according to claim 1, wherein the called side slave unit performs the receiving operation only during a period in which a control signal including a connection request signal is transmitted from the master unit.