JP2894981B2 - Digital cordless telephone system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a digital cordless telephone system.

[0002]

2. Description of the Related Art In general, a digital cordless telephone system comprises a main unit (exchange), a plurality of master units, and a plurality of slave units. The main unit (exchange) is connected to a public telephone line network and has an ISDN line. To communicate with the slaves by using the same frequency F1 to make transmission and reception different in time, and to directly communicate with the slaves without going through the master. Perform communication.

In a conventional digital cordless telephone system, when a slave unit is turned on, it receives a downlink logical control channel periodically transmitted by the master unit of the slave unit, establishes synchronization, and then receives a call from the master unit. The apparatus enters a waiting state for signal reception.

When it is desired to start communication between the slave units, the calling side slave unit measures the reception electric field level, detects an idle channel, and turns off the power supply of the wireless unit transmitter of the slave unit at an asynchronous timing in the idle channel. And sends a call signal for the called slave unit. The maximum transmission time at this time is usually set to 10 seconds for battery saving. (Radio System Development Center RCR STD-28 Chapter 6
Refer to Direct Calls between Remote Units).

[0005] On the other hand, the receiver on the receiving side is usually set in a standby state in which it waits only for the reception of an incoming call signal from the master for battery saving, and scans for the presence / absence of a caller signal on the receiving side by communication between the receivers. Do not do. Then, when trying to communicate between slave units, the receiving side is aware that there is a possibility that it will be called in slave unit communication in advance, and by manually switching to the special mode of slave unit communication, the wireless unit The power of the receiving unit is turned on and only scanning for the presence / absence of a called side slave unit calling signal by communication between the slave units is performed, and an incoming call signal from the master unit of the called side slave unit is not received.

[0006]

In this conventional digital cordless telephone system, when it is desired to start communication between slave units, a calling signal is transmitted asynchronously between a calling side and a called side, or a scan for the presence or absence of a calling signal is performed. ing.

Therefore, in order to increase the connection rate in the communication between the slave units, the time during which the calling slave unit transmits the calling signal is set to t1.
In this case, it is necessary to set the period at which the called-side slave unit turns on the power of the radio receiver and scans for the presence or absence of a calling signal to less than t1.

Accordingly, although t1 is shortened in order to reduce the battery consumption of the calling side slave unit, the receiving side slave unit has a shorter power-on cycle of the radio receiver and the receiving side battery is quickly consumed. I will. On the other hand, t1 is lengthened to reduce the battery consumption of the receiving handset, whereas the calling handset has a problem that the calling signal transmission time is long and the battery of the calling handset is quickly consumed. there were.

Further, in the conventional digital cordless telephone system, it is necessary to manually switch to a special mode dedicated to communication between slave units when communication between slave units is started for battery saving.

Therefore, it is necessary to perform communication between the slave units in advance.
There is a problem in that the user of both the calling side and the called side subunits is conscious of each other and switches modes, which is inconvenient. There is a problem in that it is impossible to receive a call by communication between child devices during standby with respect to the parent device or an incoming call from the parent device while waiting for communication between child devices.

SUMMARY OF THE INVENTION In view of the above, the present invention increases the connection rate in communication between slave units while simultaneously performing standby with respect to the base unit and standby with respect to the slave unit, and reduces the time for turning on the radio unit.
It aims to reduce battery consumption.

[0012]

A digital cordless telephone system according to the present invention comprises a main unit connected to a public telephone line network, a plurality of base units connected to an ISDN line, and a plurality of base units connected to the main unit. A digital cordless telephone system comprising a plurality of slave units each connected by a wireless line, and performing communication between the master unit and the slave unit by making transmission and reception different in time using the same frequency, The main device transmits the time information to all of the plurality of master units at a preset time via the ISDN line, and each of the plurality of master units communicates with all of the slave units. The USCCH of the downlink control channel is used while there is no need to notify the incoming call at the incoming signal reception timing that the slave always receives.
The time information is transmitted by a signal, and the child device
Based on the time information received by the SCCH signal, the time of the clock held therein is adjusted, and at the time of inter-slave communication, in which the inter-slave communication is performed between the slaves, the originating slave is preliminarily based on the received time. An uplink signal for calling the called slave unit is transmitted at a set time interval, and each of the plurality of slave units turns on an internal wireless unit power supply at the preset time interval based on the received time. Turn on and scan for the presence or absence of a call for the communication between the slaves, each of the plurality of slaves performs a call and a standby for the communication between the slaves for a limited time, and the idle time is When the standby unit performs standby for the base unit and turns on its own power supply, the base unit receives a BCCH signal in a downlink logical control channel that the base unit periodically transmits, and indicates a structure of the downlink logical control channel. Information It stores its own incoming signal reception timing, and at the time of communication between slave units, the calling slave unit receives from the calling number for communication between slave units when the calling slave unit calls the called slave unit. Uplink signal for calling the called side call at a predetermined time elapse from the called side signal timing received by the called side handset using a search table for specifying the called side signal timing And each of the plurality of slave units turns on the power of its own radio unit when the timing for receiving the uplink signal is reached at the timing when the specific time has elapsed from the incoming call signal of the own group and the slave unit. Scans for inter-machine communication calls,
Calling and waiting for the communication between the slave units limited to the timing at which the specific time has elapsed from the incoming call signal by the calling number for communication between the slave units of the called side slave unit, and waiting for the master unit during the idle time. Each of the plurality of slave units performs the time adjustment of the clock held therein once based on the time information, or the identification from the incoming call signal by the inter-slave unit communication call signal of the receiving side slave unit. The BCCH in the downlink logical control channel with which the master unit periodically communicates in the inter-child unit communication call limited to the elapsed time
Once the signal has been received, even within a position where the signal of the downlink logical control channel transmitted by the master unit cannot be received, within the allowable range of the accuracy of the clock held therein, Communication between slave units is performed within the allowable range of the internal self-running timing.

[0013]

Next, the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
(A) is a system configuration diagram showing the present embodiment, (B) is a diagram showing a configuration of a time slot of a downlink logical control channel in the present embodiment, and FIG. 2 is a communication calling method between slave units in the present embodiment. (A) is a diagram showing a time slot of a calling slave unit, and (B) is a diagram showing a time slot of a receiving slave unit.

In FIG. 1, in a digital cordless telephone system according to the present embodiment, a main unit (exchange) EX connected to a public telephone line network includes a plurality of base units BS1 and BS2.
Are connected by an ISDN line. Each base unit BS1,
BS2 has slave units PS11 and PS12 for master unit BS1 that performs communication by making transmission and reception time-different from each other using the same frequency F1, and slave unit PS2 for master unit BS2.
1, P22 are connected.

Next, the operation of this embodiment will be described with reference to FIGS.
This will be described with reference to FIG.

In the digital cordless telephone system of the present embodiment, the main unit (exchange) E is as follows.
The time is adjusted to the same time for all the slaves existing within the service area of X.

First, the main unit (exchange) EX has a clock inside, and the time information is transmitted to the base units BS1 and BS2 connected to the main unit (exchange) EX at a preset time via an ISDN line. .

The base units BS1 and BS2 receive the incoming signal at the timing of receiving the incoming signal which is always received by each of the sub units PS11, PS12, PS21 and P22. The time information from the main unit (exchange) EX is transmitted by the downlink USCCH signal (see FIG. 1B).

Slave units PS11, PS12, PS21, P
Reference numeral 22 has a clock inside, based on the time information from the main unit (exchange) EX obtained by receiving the downlink USCCH signal,
The time of the internal clock is automatically adjusted.

At the time of communication between slave units, which is one of the features of this digital cordless telephone system, for example, as shown in FIG. 2A, the originating slave unit PS11 sets a reference based on the time of the received time information and keeps it constant. An uplink signal for calling the called slave unit is transmitted only for each time (L1 time).

On the other hand, as shown in FIG. 2B, the handset PS21 in the service area of the main device sets a reference based on the reception time,
Normally, the power of the wireless unit is turned off, and the power of the wireless unit is turned on at regular time intervals (L2 hours) to scan for the presence or absence of communication between slave units. During idle time, the standby state for the base unit BS2 is performed.

Thus, the slave unit PS21 simultaneously performs the standby for the master unit BS2 and the standby for the other slave unit, and simultaneously performs the calling signal transmission of the calling-side slave unit PS11 and the scan of the called-side slave unit PS21 for calling. By limiting the time to the time, it is possible to increase the connection rate in the communication between the slave units and to reduce the time for turning on the wireless unit.

FIG. 3 is a diagram showing a configuration of a time slot in a case where the timing is limited to a timing (P * 1 TDMA) elapses from an incoming call signal of a called handset in communication between handset according to the present embodiment.

As described above, in the present embodiment, not only the control of turning on the power of the radio unit by the time adjustment of the calling side and the called side handset but also the downlink logical control channel that the base station periodically transmits. With reference to FIG. 3, a description will be given of the fact that the timing of turning on the wireless unit power is limited so that the standby time can be set for the master unit during idle time.

When the power is turned on, the receiving-side slave unit PS21 receives the BCCH (A) signal in the downlink logical control channel periodically transmitted by the base unit BS2, and stores the downlink logical control signal stored therein. From the information indicating the channel structure, it is possible to know the incoming signal reception timing that each slave unit always receives.

At the time of communication between the slave units, the calling-side slave unit PS11 determines the reception timing of the incoming call signal received by the called-side slave unit PS21 from the calling number for communication between the slave units used when calling the called slave unit PS21. Using a search table to identify
The reception timing of the incoming call signal received by the receiving-side handset PS21 is checked, and a predetermined time (P * 1T
DMA [1TDMA = 5 ms]), an uplink signal for calling the called side slave unit is transmitted, the radio unit power supply is usually turned off, and the own group's incoming signal and the own group's incoming signal When the timing to receive the downlink signal is reached at the timing when (P * 1TDAM) has elapsed from the time, the wireless unit power is turned on, the presence / absence of a communication call between the slave units is scanned, and the call for the communication between the slave units of the destination slave unit PS21 is performed. The communication between the slave units is limited to the timing (P * 1 TDMA) elapsed from the incoming call signal according to the number, and the standby is performed.
Standby for 2 is performed.

Thus, while simultaneously performing standby with respect to the base units BS11 and BS21, transmission of a call signal of the calling side handset PS11 and scanning of the call presence / absence of the called side handset PS21 are performed only at the same time, so that the child unit can be called. Increase the connection rate in inter-machine communication,
In addition, the time for turning on the wireless unit is reduced.

The communication call between the slave units limited to a certain time by the time adjustment of all the slave units within the service area of the main unit cannot receive the downlink logical control channel transmitted by the master units BS11 and BS21 once the time adjustment is completed. Even child unit P
It can be executed within the allowable range of the clock accuracy held by S11, PS12, PS21, and PS22.

The communication call between the slave units limited to the timing when (P * 1TDAM) has elapsed from the incoming call signal by the number for communication between the slave units of the receiving-side slave unit PS21, if the BCCH (A) signal is received once. Even if it becomes impossible to receive the downlink control channel transmitted by the base station BS2, it can be executed within the allowable range of the timing of the self-running downlink control signal held by the slave unit PS21.

FIG. 4 shows an example of the configuration of the slave unit and the master unit according to the present embodiment. FIG. 4A is a block diagram showing the slave unit.
(B) is a block diagram showing a master unit.

In FIG. 4A, when the slave unit transmits sound to the master unit, the slave unit of the present embodiment inputs the sound from the microphone 211 and inputs the sound to the telephone interface 210.
To the encoder 205 to encode an analog audio signal into a digital signal. The encoded signal is transmitted by the transmission unit 20
3 and input to the switch 202. Then, the signal is output to the antenna 201 via the switch 202.

When transmitting a control signal from the slave unit to the master unit, the control signal to be transmitted is transmitted to the control signal generation circuit 205.
And outputs it to the transmission unit 203 and the switch 202. The signal is output to the antenna 201 via the switch 202.

When receiving from the master unit, a down signal from the master unit is received by the antenna 201, and is output as voice from the speaker 212 via the telephone interface 210 via the switch 202. The output of the receiving unit 206 is input to a control signal receiving circuit 208 to take in a control signal from the master unit and transmit the reception timing to a timing generation circuit 209.

The timing generation circuit 209 inputs the reception timing of the input downlink signal to the switch 202, the control signal transmission circuit 204, the encoder 205, the decoder 207, and the control signal reception circuit 208. Thereby, transmission and reception with the master unit can be performed at a timing synchronized with the downlink signal. Then, a clock 213 is connected to the timing generation circuit 209 in order to realize the features of this embodiment. The timing generation circuit 209 controls ON / OFF of the switch unit 215 for supplying power from the battery 214 to the inside.

As a result, the time information input by the downstream USCCH signal from the main unit EX via the master unit BS is held.

Referring to FIG. 4B, when a master unit in the present embodiment transmits a voice from a master unit connected to a public telephone network to a slave unit, the master unit interface 1
The digital signal is input to an encoder 105 via an encoder 14 and is encoded into a digital signal used in the digital cordless telephone system. The coded signal is replied by the transmitting unit 103 and input to the switch 102. Then, the signal is output to the antenna 101 via the switch 102.

Transmission of a control signal from the master unit to the slave unit is as follows.
A control signal to be transmitted is output from the control signal generation circuit 105 and input to the transmission unit 103 and the switch 102. Then, the signal is output to the antenna 101 via the switch 102.

When performing reception from the slave unit, an uplink signal is received from the slave unit by the antenna 101 and demodulated by the receiving unit 106 via the switch 102. If the received signal is an audio signal from the slave, the decoder 107
The decoded signal, which is decoded into a signal to be used on the DN line, is transmitted from the main unit via the main unit interface 114 to the ISD.
The signal is output on the N line 115.

The timing generation circuit 109 has a TDM
A timing is generated. This timing is input to the switch 102, the control signal transmission circuit 104, the encoder 105, the decoder 107, and the control signal reception circuit 108. This allows transmission and reception with the slave unit in synchronization with the TDMA timing.

In order to realize the features of the present embodiment, a clock 16 is provided in the main unit EX, and the clock information is stored in IS.
The data is input to the timing generation circuit 109 from the DN line 115 via the main device interface 114. As a result, the time information input from the main unit EX is transmitted down the USCCH.
The signal is transmitted to the slave unit PS.

[0042]

As described above, the present invention is limited to a certain time in the time setting of all the slave units within the service area of the main unit, or from the called-side signal by the calling number between the slave units of the called slave unit. (P * 1 TDMA) A communication call between the slave units and a stand-by are performed only when the elapsed time has elapsed, and each slave unit waits for the base unit during a vacant time, thereby waiting for the base unit. To increase the connection rate in communication between slave units while reducing standby time for other slave units while reducing reception time of other slave units, and reduce the time for which the wireless unit power supply of the slave unit is turned on, thereby reducing battery consumption of the slave unit. There is an effect that can be done.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, (A) is a system configuration diagram showing the present embodiment, and (B) is a diagram showing a configuration of a time slot of a downlink logical control channel in the present embodiment. is there.

FIG. 2 is a diagram showing a communication calling method between slave units according to the present embodiment, and FIG.
(B) is a diagram showing a time slot of the receiving-side child device.

FIG. 3 is a diagram showing a configuration of a time slot in a case where communication is limited to a timing (P * TDMA) passed from an incoming call signal of a called side handset in the case of communication between handset in the present embodiment.

FIGS. 4A and 4B show a configuration of a child device and a parent device in the present embodiment, wherein FIG. 4A is a block diagram showing a child device, and FIG. 4B is a block diagram showing a parent device.

[Explanation of symbols]

 101, 201 antenna 102, 202 transmission / reception changeover switch 103, 203 transmission unit 104, 204 control signal transmission circuit 105, 205 encoder 106, 206 reception unit 107, 207 decoder 108, 208 control signal reception circuit 109, 209 timing generation Circuit 114, Main unit interface 115 ISDN line 16 Clock 210 Telephone interface 211 Microphone 212 Speaker 213 Clock 214 Battery 215 Switch unit BS1, BS2 Base unit PS11, PS12, PS21, P22 Slave unit EX Main unit (switch)

Claims (3)

(57) [Claims] 1. A main unit connected to a public telephone line network, a plurality of base units connected to the main unit via an ISDN line, and a plurality of slave units connected to each of the plurality of base units via a wireless line. In a digital cordless telephone system in which transmission and reception are made different in time using the same frequency to perform communication between the master unit and the slave unit, the main device is configured to transmit all of the plurality of master units. The ISD
The time information is transmitted at a preset time via the N line, and each of the plurality of master units receives an incoming call with respect to all of the slave units at an incoming signal reception timing that the slave unit always receives. USC of downlink control channel while broadcasting is not necessary
The slave unit transmits the time information by a CH signal, the slave unit adjusts the time of a clock held therein based on the time information received by the USCCH signal, and performs communication between the slave units. At times, the calling handset transmits an uplink signal for calling the called handset at regular intervals set in advance based on the received time, and each of the plurality of handset is based on the received time. The internal radio unit power is turned on at predetermined time intervals and a scan for the presence or absence of a call for communication between the slave units is performed, and each of the plurality of slave units is connected between the slave units limited to the certain time period. A digital cordless telephone system, wherein communication is called and standby is performed, and standby is performed for the base unit during idle time. 2. The slave unit, when turned on, receives a BCCH signal in a downlink logical control channel that the master unit transmits periodically, and receives information indicating a structure of the downlink logical control channel. It stores its own incoming signal reception timing, and at the time of communication between slave units, the calling slave unit receives from the calling number for communication between slave units when the calling slave unit calls the called slave unit. Uplink signal for calling the called side call at a predetermined time elapse from the called side signal timing received by the called side handset using a search table for specifying the called side signal timing Each of the plurality of slave units turns on the power of its own radio unit when the timing to receive the uplink signal is reached at the timing when the specific time has elapsed from the incoming call signal of the own group, and Inter-machine communication The presence / absence of the call is scanned, and the inter-slave unit communication is limited to the timing at which the specific time has elapsed from the incoming call signal according to the inter-slave unit communication call number of the called-side slave unit, and standby is performed. 2. The digital cordless telephone system according to claim 1, wherein the base unit waits for the base unit during the waiting time. 3. Each of the plurality of slave units adjusts the time of the clock held therein once based on the time information, or receives a call based on a communication call signal between the slave units of the called slave unit. When a BCCH signal in the downlink logical control channel with which the master unit is periodically communicating is once received in a call for communication between slave units limited to the timing at which the specific time has elapsed from the signal, the master unit transmits the signal. Even at a position where the signal of the downlink logical control channel cannot be received, the communication between the slave units is within the allowable range of the accuracy of the clock held therein or within the allowable range of the self-running timing of the own unit. 3. The digital cordless telephone system according to claim 1, wherein: