JP3254874B2 - Digital cordless telephone equipment - Google Patents

Abstract

PURPOSE:To satisfactorily perform the transmission processing of a control signal from each master set in the digital cordless telephone provided with plural master sets even in the case that communication with the other master sets is impossible. CONSTITUTION:In the digital cordless telephone equipment where transmission and reception of digital data are shifted from each other with respect to time to perform speaking between master sets 1, 2, and 3 and slave sets 4, 5... and a system call code common to respective master sets 1, 2, and 3 is set to realize speaking between all master sets 1, 2, and 3 and slave sets 4, 5..., the control signal from the master set 1 as the reference out of plural master sets is received by the other master sets 2 and 3, and control signals are transmitted from the other master sets 2 and 3 synchronously with the reception timing of this control signal, and the other master sets 2 and 3 transmit control signals at independent timings if failing reception of the control signal from the master set 1 as the reference.

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 master unit and a slave unit is performed by transmitting and receiving digital data.

[0002]

2. Description of the Related Art A digital cordless telephone device is configured as shown in FIG. 9, for example. In FIG. 9, reference numeral 1 denotes a base unit serving as a base station. The base unit 1 is connected to a telephone line and has an antenna 1a for communicating with a slave unit. A plurality (three in this case) of slave units capable of communicating with the master unit 1 are prepared. That is, the slave units 4, 5, and 6 are prepared, and the antennas 4a, 5a, and 6a are attached to the respective slave units 4, 5, and 6, and the antenna 1a of the master unit 1 and the antenna of each of the slave units 4, 5, and 6 are provided. 4a, 5a, 6
Wireless transmission is performed between the wireless communication device and the wireless communication device a.

When each of the slave units 4, 5, and 6 talks with 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 sent to the master unit 1.
Side, and transmits voice data converted into digital data in a time-sharing manner with the base unit 1 to make a call.

In such a digital cordless telephone device, the same frequency is used for transmission and reception, and a TDD system (time division duplex system) or a TDMA / TDD system (time division multiple access / time division system) for performing ping-pong transmission. Some methods employ a dual method.

That is, in the case of the TDD system, one channel (frequency) is temporally divided into a transmission slot T and a reception slot R, as shown in FIG. And a guard time (not shown) is provided between the slots T and R. In this case, for example, each slot T, R is 1 m
And the guard time is several tens of microseconds. Then, the mobile phone (slave) performs communication with the base station (master) in the transmission slot T, and performs reception from the base station in the reception slot R.

In the case of the TDMA / TDD system,
As shown in FIG. 10B, in the communication between one slave unit and the master unit, the transmission slot T and the reception slot R in one channel are used only once in several cycles, and The other transmission slot T and reception slot R are used for communication between another slave unit and the master unit, and are multiplexed to enable communication between a plurality of communication devices on one channel. is there.

[0007] With such multiplexing, the frequency band prepared for the cordless telephone is used efficiently. By the way, when such communication is performed, the transmission of the control signal from the master unit to each slave unit is performed in a predetermined format at predetermined intervals. That is, for example, as shown in FIG. 11A, the control signal d1 is transmitted to each slave unit for 625 μsec every 125 msec. Then, for example, when one of the slaves is called by an extension call or the like from the master, an individual number of the corresponding slave is transmitted by the control signal d1, and the corresponding slave is called. At the time of a standby operation in which each slave unit is waiting for a call from the master unit by a control signal, as shown in FIG. 11B, only this control signal is transmitted for a predetermined period (for example, 1 every 1.5 seconds). If the power of the receiving unit is intermittently turned on so as to perform intermittent reception at the same time, the power consumption required for reception in the reception standby state can be reduced accordingly. In addition, one control signal reception
Basically, it is only necessary to perform the operation for 625 μsec.
Receive for only seconds. Thus, for example, every 1.5 seconds
If the signal is received every m seconds, the time during which the receiving unit is operating is about 0.67%, and the power consumption can be greatly reduced as compared with the case where the signal is continuously received.

[0008]

By the way, as a system configuration of such a digital cordless telephone,
As shown in FIG. 1, a system having a plurality of master units has been considered. That is, in FIG. 1, reference numerals 1, 2, and 3 denote base units of a cordless telephone, respectively. The base units 1, 2, and 3 are individually connected to a telephone line and communicate with a slave unit. Antennas 1a and 2 for performing communication
a, 3a. Then, it is assumed that slave units 4, 5, 6, 7, 8} that can communicate with each of the master units 1, 2, 3 are prepared. At this time, each of the slave units 4, 5 # is capable of wireless communication with any of the master units 1, 2, 3 so that a call can be made via any of the master units. With this configuration, each child device can make outgoing calls via any of the parent devices, and can answer any incoming call to any of the parent devices, and can be applied as a cordless telephone. Spreads.

[0009] However, if the slave unit is made to be able to communicate with a plurality of master units, it is necessary for each slave unit to receive control signals from all master units during a standby operation.
Intermittent reception during the standby operation described above is not possible,
It has been difficult to reduce the power consumption during the standby operation. That is, in each of the slave units 4 and 5,
There is a possibility that it will be called by a control signal even from 2 and 3,
A control signal transmitted from the first master unit 1 and a second master unit 2
And the control signal transmitted from the third master unit 3 must be received. Here, the control signals are periodically transmitted from the master units 1, 2, and 3, but the control signals transmitted from the three master units 1, 2, and 3 do not correspond at all. Has nothing to do. Therefore,
When each of the slave units 4 and 5 is in a standby operation state,
In order to be able to receive control signals from any of the base units, it is necessary to make the receiving unit of each of the slave units power on for a very long time.

In this case, the timing at which the control signals are transmitted from all the master units 1, 2, 3 may be detected, and the power of the receiving unit of each slave unit may be turned on only at the respective transmission timings. In this case, as shown in FIG. 9, the number of times of turning on and off is three times (in the case of three masters) as compared with the case where the master is turned on only when the control signal is transmitted from one master. In addition, on / off control of the receiving unit becomes complicated.

In order to solve this inconvenience, the applicant of the present invention has first set one master unit 1 as the master unit of the master and the other master unit as the master unit of the slave. Of the control signal transmitted from the master unit 1 of the master unit so that the control signal is continuously transmitted from each master unit. -159484).

However, when the system is constructed in this manner, if any of the slave master units 2 and 3 cannot receive a control signal from the master unit 1 due to a reception failure, the control signal transmission is performed. I don't know the timing. If the transmission timing of the control signal is not known, it is impossible to transmit the control signal from the master units 2 and 3 of the slave, and the slave unit will not function as a master unit of the cordless telephone.

In view of the foregoing, the present invention provides a cordless telephone apparatus of this type in which a control signal transmission process from each base unit in a system having a plurality of base units cannot be performed with another base unit. But the goal is to make it better.

[0014]

According to the present invention, for example, as shown in FIG. 1, a plurality of master units 1, 2, 3 and slave units 4, 5,.
A call is made between the master units 1, 2 and 3 and the slave units 4 and 5 # by making the transmission and reception of digital data different in time, and the respective master units 1 and 2 are connected. , 3 are set to a common system call code, and all master units 1,
In a digital cordless telephone device capable of making a call between the base units 2 and 3 and the handset units 4 and 5, the control signal transmitted from the base unit 1 serving as a reference among a plurality of base units is transmitted to another base unit. 2 and 3 to receive the control signal.
The control signal is transmitted from the other base units 2 and 3 at the following continuous timing, and when the other base units 2 and 3 cannot receive the control signal transmitted from the reference base unit ,
The master units 2 and 3 transmit control signals at their own timing after a predetermined time has elapsed .

Further, in this case, after a predetermined time has passed since the control signal transmitted from the reference master unit 1 cannot be received, the other master units 2 and 3 transmit the control signal from the reference master unit 1. The control signal is received, and when the control signal can be received, the control signals are transmitted from the other master units 2 and 3 in synchronization with the reception timing of the control signal.

[0016]

[0017]

According to the present invention, while a control signal transmitted from a master unit serving as a reference can be received, each master unit transmits a control signal in synchronization with the control signal. The timing is always constant. When a failure occurs and the other base unit cannot receive the control signal transmitted from the reference base unit, each base unit transmits the control signal at its own timing. The control signal from the parent device can be received, and the child device can access the parent device in any case.

In this case, after a predetermined time has passed since the control signal transmitted from the reference master unit cannot be received, the other master unit performs a process of receiving the control signal transmitted from the reference master unit. When the control signal can be received, the control signal is transmitted from another master unit in synchronization with the reception timing of the control signal, so that the process of restoring the synchronization with the reference master unit can be performed. Well done.

[0019]

[0020]

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

In the present embodiment, the TDMA
This is applied to a digital cordless telephone device of the / TDD system. First, the system configuration is shown in FIG. In this example, three master units are prepared, and the first, second, and third master units 1, 2, and 3 are individually connected to a telephone line and connected to a slave unit. Antennas 1a and 2 for performing communication with each other
a, 3a. A plurality of slave units 4, 5, 6, 7, 8 # that can communicate with each of the master units 1, 2, 3 are prepared, and each of the slave units 4, 5 # Antennas 4a, 5a # for performing communication with the child device.
At this time, each of the slave units 4, 5 # is capable of wireless communication with any of the master units 1, 2, 3 so that a call can be made via any of the master units.

In this case, a common system call code is set in each of the base units 1, 2, and 3, and the control signal transmitted from each of the base units 1, 2, and 3 includes the common system call code. It is added that each slave unit is used in common,
It can be determined by this system call code. The structure of the system call code will be described. First, the downlink control signal transmitted from each master unit is shown in FIG.
It is configured as shown in FIG. That is, first, a preamble PR which is synchronous data followed by a predetermined pattern for a predetermined period of time, and thereafter, a unique word UW of a specific pattern indicating a control signal in order, and a channel type C for communication.
1, control data CAC indicating control contents, and parity CRC for error detection.

Then, the identification code shown in FIG. 8 is transmitted using predetermined bits in the control data CAC. As this identification code, the system call code is transmitted using the first 29 bits, and the additional ID is transmitted using the second 13 bits. In this additional ID, an ID individually set to each master unit is transmitted. FIG.
Is transmitted in 625 μsec.

In the present embodiment, the first master unit 1 among the three master units prepared is set as a master unit, and the other master units 2 and 3 are set as slave master units. The slave base units 2 and 3 receive the control signal transmitted from the master base unit 1 and transmit the control signals from the slave base units 2 and 3 at a timing synchronized with the reception timing of the control signal. Is sent. Specific control of the transmission timing will be described later.

Next, the structure of each of the master units 1, 2, and 3 will be described. The master unit 1 of the master and the master units 2 and 3 of the slave have the same circuit configuration, and as shown in FIG. Be composed. That is, data received from the slave unit by the antenna 31 is subjected to reception processing by the radio unit 32, and supplied to the modulation / demodulation unit 33 to demodulate the received data. The demodulated received data is supplied to the ADPCM codec unit 35 via the communication control unit 34, the received ADPCM digital data is converted into an analog audio signal, and the analog audio signal is supplied to the line interface unit 36. , Analog telephone line connection terminal 3
7 side.

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

A handset 38 is directly connected to the line interface unit 36 so that a telephone call can be made with an outside line via an analog telephone line connection terminal 37. It allows extension calls with the machine. Further, a 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, the communication control unit 34 of the master unit
The control signal is transmitted at predetermined intervals using a dedicated channel (frequency band) prepared for transmitting the control signal, and another child device is called by this control signal. In this case, the same system call code is added to the control signal transmitted from each master unit, and the distinction between the master and the slave is notified by an additional ID transmitted after the system call code.

In this example, the communication control units 34 of the slave master units 2 and 3 control to receive a control signal transmitted from the master master unit 1. That is, the control signal including the system call code to which the master ID is added is received and determined. Basically, the communication control unit 34 controls the slaves 2 and 3 of each slave to periodically transmit the control signal in synchronization with the timing at which the control signal is received from the master. In this case, in the present example, the master units 2 and 3 of each slave synchronize with each other based on the timing at which the preamble as the synchronization data, which is the first signal transmitted as the control signal, is received. However, when the slave base units 2 and 3 cannot receive the control signal from the master base unit 1, the communication control unit 34 of each base unit controls the transmission timing of the control signal at a unique timing.

Next, FIG. 3 shows the configuration of the slave units 4, 5 # used in the cordless telephone of this embodiment. In FIG. 3, reference numeral 11 denotes an antenna. Data received by the antenna 11 from the master unit or another slave unit is received by the radio unit 12 and supplied to the modem unit 13 to demodulate the received data. Then, the demodulated reception data is transmitted to A via the communication control unit 14.
The AD supplied to the DPCM codec 15 and received and obtained
The PCM digital data is converted into an analog audio signal, and the analog audio signal is output from the speaker 16.

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

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, a display unit 20 is connected to the man-machine interface unit 19 to display an operation state and the like.

The communication control unit 14 controls the receiving operation so as to receive, at a predetermined interval, only a control signal transmitted from the master unit through a predetermined control channel when the communication unit 14 is in a standby state. . In this case, the system call code included in the control signal is determined to determine whether or not the control signal is for the system to which the slave unit belongs. Further, the control signal transmitted from the master unit 1 of the master is determined by the additional ID transmitted after the system call code, and the control signal is periodically transmitted based on the reception timing of the control signal from the master unit 1 of the master. Intermittent reception. This receiving process will be described later.

If the received control signal is a control signal of the system to which the slave unit belongs, the content of the received control signal is determined, and the slave unit is identified by the connection request signal included in the control signal. When it is determined that it is being called, the slave unit is caused to perform the corresponding operation. When each of the slave units is called by this connection request signal, a communication is performed with the base unit for an extension call or an outside line call, and a communication is performed with another slave unit for the extension call. May be performed. When it is desired to make a call from each slave unit for an external call or an extension call (extension call with the master unit and a call between slave units), a connection request signal is sent to the master unit using the control channel. To send.

Next, a state in which a control signal is transmitted from each of the master units 1, 2, and 3 having the above-described configuration to each of the slave units 4 and 5 # will be described. Is transmitted in the state shown in FIG. 4A. That is, one transmission of the control signal for 625 μsec is performed continuously at a cycle of 125 msec. The period during which the waveform of A in FIG. 4 rises is the period during which the control signal is transmitted.

The slave base units 2 and 3 receive the control signal transmitted from the master base unit 1 and transmit the control signal in synchronization with the reception timing. Here, the control signal is transmitted from the second master unit 2 5 ms after the start of the reception of the master control signal (see FIG. 4B), and the third master unit 3 10 ms later. Transmits a control signal (see FIG. 4C). Therefore, [10 ms + 625 μm
[Sec], the control signals are continuously transmitted from the three master units 1, 2, and 3.

When each of the slave units 4, 5 # is in the standby state, the power supply of the receiving unit (such as the wireless unit 12) is turned off only at the timing when the series of control signals are continuously transmitted. It is turned on periodically. Here, as shown in FIG. 4D, the first (master) master unit 1
From the start of transmission of the control signal from the third master unit 3
The power of the receiving unit is turned on only during a period T _ON during which the transmission of the control signal ends. However, actually, it takes some time (for example, 25 μsec) for the receiving unit to start up, and therefore, the _ON time T _ON is set to the above-mentioned time [10 ms + 625].
μsec] and a rise time of about 25 μsec. By performing such control, the operation time of each of the slave units 4, 5 # in the standby state can be significantly reduced.

By the way, such control is possible because:
In this case, the control signals transmitted from the master unit 1 of the master can be received by the master units 2 and 3 of the slaves. There is a possibility that a case where reception is not possible with the devices 2 and 3 may occur. For example, when the master unit 1 of the master breaks down and stops transmitting the control signal, or when some kind of radio interference occurs, the control signal transmitted from the master unit 1 of the master is transmitted to the master units 2 and 3 of the slaves. May not be able to receive data correctly.

In such a case, the slave base units 2 and 3 of this embodiment transmit the downlink control signal at their own timing. Hereinafter, the specific processing will be described. First, as shown in FIG.
In a state in which the downlink control signal at 125m seconds interval is transmitted from, and the control signal from the predetermined timing T ₁ is no longer transmitted (or can not be received by the slave to be transmitted).

The reception of the control signal is performed by the slave master units 2 and
5, as shown in FIG. 5B, the master units 2 and 3 of each slave cannot obtain reference synchronization data, and cannot know the timing of transmitting the downlink control signal. To stop. That is, FIG. 5B shows the transmission state of the control signal in the second master unit 2. After the timing T ₁ at which the control signal is no longer transmitted from the master unit 1, the slave unit 2 transmits the control signal. The transmission of the control signal also stops. In this example, if the slave base units 2 and 3 cannot receive the control signal from the master base unit 1 for 5 consecutive seconds, the communication control unit 34 of the slave base units 2 and 3 Then, the downlink control signal is transmitted at an interval of 125 ms at a unique timing. That is, for example in the second base unit 2, as shown in B of FIG. 5, the timing T ₂ in which reception has passed is approximately 5 seconds can not be from the master, resume sending downlink control signal at 125m sec intervals I do.
At this time, the control signal transmitted from the master unit of the slave is a control signal having the same data configuration as the control signal transmitted when synchronized with the master.

In this way, the master units 2 and 3 of each slave
By transmitting the downlink control signal at its own timing,
Each of the slave units 4 and 5 # can receive at least a control signal from the slave master units 2 and 3 to respond to an incoming call. For example, there is a case where no control signal is transmitted from the master master unit 1. Even if this occurs, the system configuration as a cordless telephone is ensured, and it becomes possible for the slave unit to receive an external line received by the slave base units 2 and 3.

The slave master units 2 and 3
When the transmission of the control signal is started at its own timing, the control signal is received from the master unit 1 of the master every predetermined time (here, every 10 seconds) under the control of the communication control unit 34 in the master unit of the slave. Perform processing. That is, for example, as shown in FIG. 6A, in a state where the control signal is not transmitted from the first master unit 1, as shown in FIG. When the control signal is transmitted at 125 ms intervals at this unique timing for 10 seconds while the control signal is transmitted at intervals of 125 ms, the transmission of the control signal is temporarily stopped and shown in FIG. 6C. In this way, the control signal receiving process (setting of the control signal receiving channel and discrimination of the received data) is performed only for 500 ms. That is, as shown in FIG. 2, the master unit of this example is configured to perform transmission and reception in a time-division manner, and it is necessary to stop the transmission process at the time of the reception process. In FIG. 6, C indicates a period in which the high level period is a period during which a process of receiving a control signal from the master unit 1 of the master is being performed.

When the control signal from the master unit 1 cannot be received in the receiving process for 500 ms,
As shown in FIG. 6B, 125 m at a unique timing
The transmission of the control signal at the second interval is restarted. After that, this 10
The transmission of the control signal at intervals of 125 ms for seconds and the reception processing of the control signal for 500 ms are repeated.

When the control signal is received from the master unit 1 of the master during the control signal reception processing for 500 ms, the reception processing of this control signal is stopped and the preamble included in the received control signal is received. The control signal is transmitted based on the timing. For example, the second
When the parent device 2 can receive a control signal transmitted to the timing T ₃ shown in A of FIG. 6, as shown in C of FIG. 6, the immediately stops the reception process of the control signal at this time, this After a predetermined time T ₄ (see FIG. 6B) necessary for the process of synchronizing with the received control signal has elapsed, transmission of the control signal synchronized with the control signal of the master unit 1 of the master is started. Thereafter, as long as the control signal from the master can be received, the control signal is transmitted at intervals of 125 msec while the synchronization is ensured.

As described above, when the control signal is transmitted from the master units 2 and 3 of the slave at an independent timing, it is determined whether or not the control signal from the master can be received at predetermined time intervals. Returns to the process synchronized with the master, so that an appropriate control signal transmission process is always performed, and the control of the slave unit can be always performed well.

In the process of receiving a control signal during standby in each of the slave units 4, 5 #, when the control signal from the master unit 1 cannot be received, synchronization with the master unit is lost. Since the judgment is made and the process for synchronizing with the control signal transmitted from the master unit is performed again, at this time, the control signal is synchronized with the control signal transmitted from the master units 2 and 3 of each slave, which can be dealt with.

Although the above embodiment has been described with reference to a case where the number of master units is three, the number of master units and slave units is not limited as long as the system includes a plurality of master units. Also,
The configuration of the control signal and the setting of the interval of transmission / reception processing shown in the above-described embodiment are merely examples, and are not limited to the above-described embodiment.

[0048]

According to the present invention, when some trouble occurs in the transmission of the control signal from the reference master unit and the other base unit cannot receive the control signal transmitted from the reference master unit, Since each master transmits a control signal at its own timing, the slave can receive a control signal from any master, and in any case, the slave can access the master, and always The system configuration as a cordless telephone is secured.

In this case, after a predetermined time has passed since the control signal transmitted from the reference master cannot be received, the other master performs reception processing of the control signal transmitted from the reference master. When the control signal can be received, the control signal is transmitted from another master unit in synchronization with the reception timing of the control signal, so that the process of restoring the synchronization with the reference master unit can be performed. Well done.

[0050]

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a cordless telephone according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a parent device according to one embodiment.

FIG. 3 is a configuration diagram of a child device according to one embodiment.

FIG. 4 is a timing chart showing a transmission / reception state of a control signal according to one embodiment.

FIG. 5 is a timing chart showing a downlink control signal transmission state at the time of occurrence of a failure according to one embodiment;

FIG. 6 is a timing chart showing a state of synchronization recovery processing between master units according to the embodiment;

FIG. 7 is an explanatory diagram showing a configuration of a control signal according to one embodiment.

FIG. 8 is an explanatory diagram illustrating a configuration of an identification code according to an embodiment;

FIG. 9 is a configuration diagram showing a system configuration of a conventional cordless telephone device.

FIG. 10 is a configuration diagram showing a communication system.

FIG. 11 is a timing chart showing a conventional control signal transmission / reception state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st master (master master) 2 2nd master (slave master) 3 3rd master (slave master) 4,5,6,7,8 Slave unit 12,32 Radio unit 13,33 Modulation / demodulation unit 14,34 Communication control unit

Claims (2)

(57) [Claims] 1. A communication system comprising a plurality of master units and a slave unit, wherein transmission and reception of digital data are performed at different times between the master unit and the slave unit, and a call is made between the master unit and the slave unit. In a digital cordless telephone device in which a common system call code is set in the base unit so that a call can be made between all of the base units and the handset, the base unit serving as a reference among the plurality of base units A control signal transmitted from the other base unit is received by the other base unit, and a control signal is transmitted from the other base unit at a timing continuous to the reception timing of the control signal. When the control signal transmitted from the master unit cannot be received, the other master units
Later, a digital cordless telephone device that sends control signals at its own timing. 2. After a predetermined time has elapsed since the control signal transmitted from the master unit serving as the reference cannot be received,
The other master unit performs a receiving process of a control signal transmitted from the reference master unit. When the control signal can be received, the other master unit synchronizes with the reception timing of the control signal, and receives the control signal from the other master unit. 2. A control signal is transmitted.
Digital cordless telephone device as described.