JP2830231B2 - Cordless telephone calling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The description will be made in the following order.

A Industrial Field of Use B Outline of the Invention C Prior Art D Problems to be Solved by the Invention E Means for Solving the Problems (FIG. 1) F Function G Examples (FIGS. 1 to 5) H The present invention relates to a method of talking on a cordless telephone.

B SUMMARY OF THE INVENTION The present invention provides a cordless telephone that intermittently monitors reception only on registered channels among channels that are permitted to be used during standby, by performing predetermined processing. It effectively allows all channels to be used.

C Conventional technology In a low-power cordless telephone in Japan, 87 communication channels and 2 control channels are prepared (both channels are duplex channels).

Therefore, the handset (slave unit) monitors the control channel only for 120 msec during standby, for example, every 3 seconds, and enters the sleep mode (power down mode) during the remaining period, thereby suppressing battery consumption. .

However, even in Japan, no control channel is provided for a weak type cordless telephone.

In the United States, ten channels from a first channel to a tenth channel are prepared for a cordless telephone, but no control channel is prepared.

Therefore, in a cordless telephone in which these control channels are not prepared, the consumption of the battery of the handset is suppressed by a method as shown in FIG.

That is, since the base unit (base unit) operates on the commercial AC power supply, the first channel to the tenth channel are in standby mode.
The reception monitoring of the channels is sequentially performed, and the reception monitoring is repeated to wait for a connection request from the handset. At this time, the time required to detect a connection request from the handset is about 120 ms per channel, and thus all channels are repeatedly scanned at a cycle of about 1.2 seconds.

In addition, the handset monitors reception, for example, on the third channel, and then monitors reception on the seventh channel to check for a connection request from the base unit during standby.
If there is no connection request, thereafter, for example, the operation of entering the sleep mode for 3.5 seconds is repeated.

Therefore, when the handset is in the standby mode during the standby mode most of the time, the consumption of the battery can be suppressed.

Next, the configuration and operation of such a cordless telephone will be specifically described. During standby, the channel that the handset is monitoring for reception is
It is assumed that the channel is the third channel and the seventh channel.

In FIG. 4, (1) shows a handset, (2) shows a base unit, and (3) shows a telephone line (external line).

In the handset (1), (110) is its transmitting circuit, (120) is its receiving circuit, and the transmitting circuit (11
0) converts the voice signal St and the command signal CMND (to be described in detail later) into an upstream channel FM signal Su and transmits the signal. The receiving circuit (120) receives the downstream channel FM signal Sd and It demodulates the audio signal Sr and the command signal CMND. Further, in the receiving circuit (120), for example, by detecting the presence or absence of an intermediate frequency signal,
A detection signal SQLC indicating the presence or absence of the downlink channel FM signal Sd is also extracted.

In the handset (1), (131) is a dial key, (132) is a talk key, and the talk key (1) is used.
Reference numeral 32) denotes a non-locking type push switch. Each time the key (132) is pressed, the handset (1) alternately switches between a standby mode and a talk mode. When the handset (1) is in the standby mode, the handset (1) is waiting for a call from the handset (1), and two of the downlink channels,
In this case, as shown in FIG. 9, the third channel and the seventh channel are intermittently monitored to wait for a connection request from the base unit (2). In the talk mode, continuous reception and transmission are performed with the base unit (2).

Further, (133) to (137) are auxiliary keys such as a redial key constituted by a non-lock type push switch, (139) is a ringer speaker, and (140) is a microcomputer for system control. Then, in the microcomputer (140), the transmission circuit (110)
And the command signal CMN extracted from the receiving circuit (120).
D and the detection signal SQLC are determined. The microcomputer (14
In 0), a control signal for permitting / prohibiting transmission / reception of the transmission circuit (110) and the reception circuit (12) and specifying a channel
TCTL and RCTL are also formed.

Also, (141) and (142) are memories, and memory (141)
Is a ROM, and the ROM (141) includes a code 25 for distinguishing the cordless telephone from other cordless telephones.
A bit system identification code SYID is stored. Further, the memory (142) is a RAM, and the RAM (142) stores channel data CHDT indicating the channel monitored by the handset (1) during standby, in this case, the third channel and the seventh channel. Stored.

Also, (151) indicates a battery for power supply, and this battery (15
1) is a rechargeable battery such as a nickel-cadmium battery, and this output voltage is supplied to each part of the handset (1) as its operating voltage.

On the other hand, the base unit (2) is a handset (1)
Has a transmitting circuit (210) and a receiving circuit (220) similar to the transmitting circuit (110) and the receiving circuit (120), and the receiving circuit (220) receives an incoming call from the telephone line (3) in the standby mode. While waiting for a call, as shown in FIG. 9, it scans and receives all the up channels and waits for a connection request from the handset (1).
In the talk mode, continuous reception and transmission are performed with the handset (1).

Further, in the base unit (2), (231) is a 4-wire / 2-wire conversion circuit, (232) is a switch circuit corresponding to a hook switch of a general telephone, and (233) is a dial tone signal (DTMF signal). A forming circuit (234) is a ring tone signal detecting circuit.

Also, (240) is a microcomputer for system control. This microcomputer (240) performs the same processing as the microcomputer (140) in the handset (1) and manages the entire operation of the cordless telephone. is there. Further, (241) and (242) are memories, which correspond to the memories (141) and (142),
The system identification code SYID is written in the ROM (241),
The RAM (242) stores the data CHDT of the channel being monitored for reception by the handset (1).

FIG. 5 shows an example of a signal format of the command signal CMND. This signal CMDN has a 24-bit bit synchronization signal BSYN at the beginning, and then a 16-bit frame synchronization signal.
Has FSYN. In this case, these signals BSYN and FSYN are, for example, BSYN = “101010 ‥‥‥‥‥‥ 10” FSYN = “1100010011010110” ‥‥ for the up channel FSYN = “1001001100110110” ‥‥ for the specific bit indicated for the down channel Has a pattern.

Further, the command signal CMND has a 25-bit system identification code SYID, a 12-bit error correction code ECC for the code SYID, and a 3-bit dummy bit DBIT in order following the signal FSYN. DB
Following the IT, there is a 5-byte control code CTRL.

In this case, the control code CTRL is the first byte CTL1
Is a code indicating the control contents of the handset (1) and the base unit (2), and the second to fifth bytes CTL2 to CTL5 are parameters or data related to the first byte CTL1.

When the handset (1) or the base unit (2) receives the command signal CMND,
In the microcomputer (140) or (240), the signal CM
It is checked whether or not the identification code SYID included in the ND matches the identification code SYID stored in the ROM (141) or (241). Only when the identification code SYID matches, the command signal CMND is validated. If not, it is invalid.

[Standby]

At the time of standby, the operation as shown in FIG. 9 and the operation as shown in the upper part of FIG. 6 and the like are performed.

That is, in FIG. 6, the solid line in the vertical direction indicates the state of the handset (1) and the base unit (2). The vertical direction of the solid line is the time axis direction, but for the sake of drawing, the time axis is not linear. When the solid line is a single line, the sleep mode is set. When the solid line is a double line, only the reception is permitted, and during the hatched period, transmission is also permitted.

Then, in the handset (1), the RAM (142)
The third and seventh downstream channels are monitored alternately and intermittently in accordance with the channel data CHDT stored in.

In the base unit (2), all uplink channels are repeatedly scanned and received.

[Call from handset]

A call from the handset (1) to an outside line may be, for example,
This is performed as in the connection sequence shown in the figure.

That is, when the talk key (132) is pressed while the handset (1) is in the standby mode, this is detected by the microcomputer (140), whereby the receiving circuit (1) is detected.
20) performs reception on the third or seventh downstream channel indicated by the channel data CHDT stored in the RAM (142).
If the channel is free, the receiving channel of the receiving circuit (120) is fixed to the third downstream channel, and continuous reception is permitted. Further, transmission of the transmission circuit (110) is permitted in the third upstream channel. Therefore, the handset (1) is in the talk mode on the third channel.

Subsequently, a command signal CMND in which the control code CTRL indicates a request for calling is repeatedly supplied from the microcomputer (140) to the transmission circuit (110).
Is converted into an upstream third channel FM signal Su, and this signal Su is transmitted through the antenna (100) to the base unit (2).
Sent to

Then, in the base unit (2), the signal (radio wave) Su is received by the antenna (200). However, since the receiving circuit (220) repeatedly scans all the up channels, the receiving channel is set to the third channel. , A detection signal SQLC is obtained from the receiving circuit (220). Then, the receiving circuit (22
0) scanning is stopped, and then the receiving circuit (220) demodulates the command signal CMND from the FM signal Su. This signal CMND is supplied to the microcomputer (240), and the identification code SYID included in the signal CMND is It is checked whether it matches the identification code SYID of the ROM (241).

And, in this case, since they match and the control code CTRL included in the signal CMND indicates a request for calling,
The microcomputer (240) permits the transmission circuit (210) to transmit on the channel that has received the FM signal Su, in this case, on the third downstream channel. Therefore, the base unit (2) is also in the talk mode on the third channel.

Then, the command signal CMND for the response to the call request
Is supplied from the microcomputer (240) to the transmission circuit (210),
In the transmission circuit (210), the signal CMND is converted into a downstream third channel FM signal Sd, and this signal Sd is transmitted to the handset (1) through the antenna (200).

Then, in the handset (1), when the FM signal Sd is transmitted from the base unit (2) through the downlink third channel, the FM signal Sd is received by the antenna (100) and supplied to the receiving circuit (120). The command signal CMND is extracted from (120) and the microcomputer (140)
Supplied to

Then, the identification code included in the command signal CMND
SYID matches the identification code SYID stored in the ROM (141), and the control code included in the signal CMND.
Since CTRL indicates a response to the call request, the transmission circuit (110) and the reception circuit (120) determine the talk mode in the third channel.

Therefore, the handset (1) and the base unit (2) are connected through the third channel.

Further, in the base unit (2), the switch circuit (232) is set to an off-hook state and the transmission circuit (210)
And the receiving circuit (220) is connected to the line (3) through the conversion circuit (231) and the switch circuit (232).

Therefore, the handset (1) is connected to the line (3) through the base unit (2).

[Dial and call]

Subsequently, when the caller inputs the telephone number of the other party using the dial key (131) of the handset (1), a command signal CMND indicating that the control code CTRL is the transmission of the telephone number and the telephone number is formed. , This signal CMND,
It is converted into an upstream FM signal Su and transmitted.

Therefore, in the base unit (2), the command signal CMND is obtained from the receiving circuit (220). Since the control code CTRL of the signal CMND indicates that the telephone number is to be transmitted and indicates the telephone number. The forming circuit (233) is controlled by the microcomputer (240) in accordance with the telephone number to form a dial tone signal corresponding to the telephone number sent from the handset (1), and this signal is converted to a conversion circuit (231). Through the switch circuit (232) to the telephone line (3).

Then, when the other party answers the telephone, an audio signal Sr from the other party is supplied to the transmission circuit (210) through the signal line of the line (3) → the switch circuit (232) → the conversion circuit (231). Therefore, the signal Sr is converted into a downlink FM signal Sd, and this signal Sd is transmitted from the antenna (200).

Then, the signal Sd is received by the handset (1), and the audio signal Sr is extracted from the receiving circuit (120).
This signal Sr is supplied to the receiver (121).

At the time of transmission, the audio signal St from the transmitter (111) is transmitted.
Is supplied to the transmission circuit (110) and converted into an upstream FM signal Su, and this signal Su is transmitted from the antenna (100) to the base unit (2).

Then, the signal Su is received by the base unit (2), and a signal St is extracted from the receiving circuit (220). The signal St is converted into a conversion circuit (231) and a switch circuit (232).
Is supplied to the line (3) and sent to the other party's telephone.

[End talk]

When the call is finished, for example, as shown in FIG. 7, when the talk key (132) of the handset (1) is pressed, a command signal CMND indicating that the control code CTRL is the end of the call is formed, and this signal CMND is generated. Is transmitted to the base unit (2) by the upstream FM signal Su.

Then, the command signal CMND is extracted from the receiving circuit (220) of the base unit (2), and the microcomputer (240) determines that the call has ended. As a result, while the transmission of the transmission circuit (210) is prohibited, the reception circuit (2
20) is a state in which all the up channels are repeatedly scanned, that is, the standby mode is set. Further, the switch circuit (232) is also brought into the on-hook state.

Further, also in the handset (1), after transmitting the command signal CMND indicating the end of the call, the transmitting circuit (110) is prohibited from transmitting, and the receiving circuit (120) again transmits the third and seventh downlink channels. Are alternately and intermittently received, that is, a standby mode is set.

[Incoming call to handset]

The incoming call from the outside line to the handset (1) is, for example, the eighth
This is performed as in the connection sequence shown in the figure.

That is, when a call is received through the line (3), the ring tone signal is detected by the detection circuit (234), and this detection signal is supplied to the microcomputer (240). Then, this causes the receiving circuit (220) to store the RAM (24
Reception is performed on the third channel or the seventh channel indicated by the channel data CHDT stored in 2), and if either channel, for example, the third channel is free, the reception channel of the reception circuit (220) is Fixed to the third upstream channel. Further, transmission of the transmission circuit (210) is also permitted in the third downlink channel. Therefore, the base unit (2) is in the talk mode on the third channel.

Subsequently, a command signal CMND in which the control code CTRL indicates an incoming call request is repeatedly supplied from the microcomputer (240) to the transmission circuit (210), and the signal CMND is output to the downstream third channel FM.
The signal is converted into a signal Sd and transmitted to the handset (1).

Then, in the handset (1), the antenna (10
0) receives the signal Sd, but the receiving circuit (120)
According to the channel data CHDT of the RAM (142)
Since the downstream third channel and the seventh channel are alternately and intermittently scanned repeatedly, when the receiving channel becomes the third channel, the receiving circuit (12
0), the detection signal SQLC is obtained. Then, scanning of the receiving circuit (120) is stopped in the third channel, and then the command signal CMND is demodulated from the FM signal Sd in the receiving circuit (120), and the identification code included in the signal CMND is included.
It is checked whether the SYID matches the identification code SYID of the ROM (141).

Then, in this case, since they match and the control code CTRL included in the signal CMND indicates a request for an incoming call,
The transmission circuit (110) receives the FM signal Su,
In this case, transmission is permitted on the third upstream channel. Therefore, the handset (1) is also in the talk mode on the third channel.

Next, a command signal CMND for responding to the incoming call request
Is supplied from the microcomputer (140) to the transmission circuit (110),
This signal CMND is converted into an upstream third-channel FM signal Su and transmitted to the base unit (2).

Then, in the base unit (2), the FM signal Su is transmitted from the handset (1) through the third upstream channel.
Is transmitted, the command signal CMND is extracted from the receiving circuit (220) and supplied to the microcomputer (240).

Then, the identification code included in the command signal CMND
The SYID matches the identification code SYID stored in the ROM (241), and the control code included in the signal CMND.
Since the response to the CTRLga call request is shown, the transmission circuit (210) and the reception circuit (220) determine the talk mode in the third channel.

Therefore, the handset (1) and the base unit (2) are connected through the third channel.

Further, in the handset (1), the microcomputer (140) controls the oscillation circuit (138) to form a ringer signal, and this signal is supplied to the speaker (139) to notify the call from the speaker (139). A bell sounds.

Then, when the talk key (132) is pressed in the handset (1), the control code CTRL indicates that the talk key (132) has been pressed.
An MND is formed, this signal CMND is transmitted by the FM signal Su, and the oscillation circuit (138) is turned off to turn off the ringer.

And the command signal from this handset (1)
When the CMND is received by the base unit (2), the switch circuit (232) is turned off-hook.

Therefore, a communication channel is opened between the handset (1) and the base unit (2), and thereafter, a call can be made between the other party and the handset (1).

D Problems to be Solved by the Invention However, in the case of the standby method as described above,
The handset (1) has, for example, a third channel and a seventh channel.
Since only two of the channels are monitored for reception, the base unit (2) can effectively use only two of the ten channels when receiving a call.

In this case, at the time of an incoming call, the third channel and the seventh channel
If a channel is used, there will be no available channels even if all other channels are free, and it will not be possible to receive a call.

That is, although use of ten channels is permitted, only two channels can be used effectively.

However, if the handset (1) also scans all the down channels repeatedly like the base unit (2) during standby, the sleep mode period must be shortened, and the battery ( 151) consumption will increase.

The present invention is intended to solve such a problem.

E Means for Solving the Problems Therefore, in the present invention, the handset (1)
And the base unit (2) executes processing as shown in FIGS. 1 to 3, for example.

F operation In standby mode, the handset monitors only two channels, but can effectively use all channels.

G. Embodiment First, the microcomputer (140) is provided with, for example, a routine (300) of a flowchart as shown in FIG. 1, and the microcomputer (240) is provided with a routine (300) of a flowchart as shown in FIG. 400) is provided.

In the RAMs (142) and (242), an address for storing channel data EMCH for an unused channel is prepared in addition to the registration address of the channel data CHDT for a call.

Assuming now that the handset (1) and the base unit (2) are operating normally, in the base unit (2), during standby, all uplink channels are repeatedly scanned and monitored for reception. ,
At this time, if there is a vacant channel, all of the vacant channels are used as vacant channel data EMCH.
Registered in RAM (242). The data EMCH in the RAM (242) is constantly updated as the channel is scanned.

At the end of the call, the microcomputers (140) and (240) execute the routines (300) and (400), and the RAM (142)
The channel data CHDT of (242) is updated. In addition,
FIG. 3 shows a protocol when the update of the channel data CHDT is performed normally. The numerals on both sides are reference numerals (reference numerals) of steps in the routines (300) and (400).

That is, during a call, the handset (1) and the base unit (2) are connected through a channel, and the base unit (2) is connected to the telephone line (3) to perform a call.

During the call, in the handset (1), the microcomputer (140) checks the talk key (132) in step (301), and when the key (132) is not pressed, the microcomputer (140) The process repeats step (301), so the state of key (132) is constantly checked during a call.

In the base unit (2), the microcomputer (240) checks in step (401) whether it can receive a command signal CMND for ending the call from the handset (1), and if the signal CMND cannot be received. , The processing of the microcomputer (240) repeats the step (401), and thus, during the call, the command signal CMND for ending the call
Receiving is always checked.

Then, when the talk is over and the talk key (132) is pressed, this is detected in step (301), and the process proceeds from step (301) to step (302). In this step (302), the control code CTRL is set. A command signal CMND indicating the end of the call is transmitted to the base unit (2), and then the process proceeds to step (303).

Then, in the base unit (2), this signal
CMND is detected in step (401), and the process proceeds from step (401) to step (402). In this step (402), the channel data CHDT of RAM (242) is read.
It is checked whether the channel indicated by is an empty channel. This check is performed by comparing the channel data CHDT with the empty channel data EMCH stored in the RAM (242).

If the result of the check is normal, that is, if the channel indicated by the data CHDT is an empty channel, the process proceeds from step (402) to step (403). In this step (403), the switch circuit (23)
2) is set to the on-hook state, and then, in step (404), a command signal CMND is formed which indicates that the control code CTRL is an end-of-call response and that the channel data CHDT is normal. Handset (1)
Sent to

Then, in step (303), this step (4
04), the command signal CMND is received and checked. In this case, the content of the command signal CMND is the end-of-call response and the channel data CHDT of the base unit (2)
Is normal, the process proceeds from step (303) to step (304), and this step (30)
In 4), as described with reference to FIG. 9 and the like, the standby mode in which the two channels indicated by the channel data CHDT are monitored alternately and intermittently is set. Further, in this standby mode, the setting is made such that, when a connection is made to the base unit (2) by calling or the like, the connection is made on any available channel. Thereafter, the standby mode for the two-channel intermittent reception is entered.

In the base unit (2), the process proceeds to step (405) following step (404). In this step (405), all channels are repeatedly scanned as described in FIG. The standby mode for monitoring the reception is set. Also,
In this standby mode, the setting is made such that when connection to the handset (1) is made by an incoming call or the like, the connection is made on the two channels indicated by the channel data CHDT. Thereafter, the operation enters a standby mode for receiving all channels.

Therefore, both the handset (1) and the base unit (2) have entered the standby mode.

However, when the result of the check is abnormal in step (402), that is, when the channel indicated by the data CHDT is used, the process proceeds from step (402) to step (411), and in this step (411) Command signal CM indicating that the control code CTRL is a response to the end of call and that the channel data CHDT is abnormal.
An ND is formed and this signal CMND is transmitted to the handset (1).

Subsequently, the process proceeds to step (412). In this step (412), the control code CTRL is a command indicating that the free channel data EMCH is to be transmitted and the free channel data EMCH stored in the RAM (242). signal
A CMND is formed, this signal CMND is transmitted to the handset (1), and the process proceeds to step (413).

Then, in step (303), step (411)
The command signal CMND is received and checked. In this case, since the content of the command signal CMND indicates that the end-of-call response and the channel data CHDT of the base unit (2) are abnormal, Is the step (30
Proceed from step 3) to step (311). Then, in this step (311), all uplink channels are sequentially monitored for reception to detect empty channels, and all of the detected empty channels are replaced with empty channel data EM.
It is registered in the RAM (142) as a CH, and then the step (31)
Proceed to 2).

Then, in step (312), step (412)
The command signal CMND is checked for reception, and if received, the process proceeds from step (312) to step (313).
And in this step (313), step (31)
The free channel data EMCH obtained in 1) and step (41)
The free channel data EMCH sent in 2) is compared, and data HBEM indicating a channel which is a free channel in both data EMCH and EMCH is extracted.

In this case, as described later, of the channels indicated by the data HBEM, two channels are registered in the RAMs (142) and (242) as channel data CHDT.
When the data HBEM is not obtained for two channels, the channel which is an empty channel in the base unit (2) is adopted as the data HBEM. When there is no data HBEM, the current channel and the channel next to the current channel are used. Is adopted for data HBEM.

However, the channel number of the cordless telephone in the United States and its frequency have a relationship as shown in FIG. 10 and the frequency interval is irregular, so that the combination of the channels is the second channel and the third channel. Channel 6 Channel 3 and Channel 5 In any of Channels 5 and 7, when one channel is subject to interference such as interference by another cordless telephone, the other channel is also affected simultaneously. I will. For example,
When the second channel is disturbed, the third channel is also disturbed (when the intermediate frequency is 10.695 MHz).

Therefore, such a combination of channels is
Excluded from HBEM.

Next, in step (314), the control code CTRL
Is transmission of data HBCH and step (313)
A command signal CMND indicating the data HBEM obtained in step (1) is formed, the signal CMND is transmitted to the base unit (2), and the process proceeds to step (315).

Then, the signal CMND is detected in step (413), and the process proceeds from step (413) to step (414). In this step (414), the control code CTRL is set to the command signal CMND indicating a response to the reception of the data HBEM. Is transmitted to the handset (1), and the process proceeds to step (415).
Proceed to.

Then, in step (315), when the signal CTRL is detected, the processing proceeds from step (315) to step (3).
Proceeding to 16), in this step (316), a command signal CMND indicating that the control code CTRL is determined is transmitted to the base unit (2), and the process proceeds to step (317).
In this step (317), the data HBEM is registered in the RAM (142) as channel data CHDT.

Subsequently, in step (318), step (304)
Similarly to the above, the standby mode for alternately and intermittently monitoring the two channels indicated by the channel data CHDT is set. In this standby mode,
When connecting to the base unit (2) by making a call or the like, the setting is also made so that the connection is made on any available channel. Thereafter, the standby mode for the two-channel intermittent reception is entered.

Also, in the base unit (2), the command signal CTRL sent in step (316) is changed to step (4).
15), the process proceeds from step (415) to step (416), and in this step (416),
Data HBEM is registered in RAM (242) as channel data CHDT.

Subsequently, in step (417), step (405)
Similarly to the above, a standby mode for repeatedly scanning all channels and monitoring reception is set. In this standby mode, when connecting to the handset (1) due to an incoming call or the like, the channel data CHDT
The setting is also performed so as to perform the operation on two channels indicated by. Thereafter, the operation enters a standby mode for receiving all channels.

Therefore, both the handset (1) and the base unit (2) have entered the standby mode.

Further, in step (312), when the command signal CMND of the free channel data IMCH in step (412) cannot be received, the processing proceeds from step (312) to step (321). It is checked whether a predetermined time limit, for example, 41 seconds, has elapsed since the execution of (312).

Then, in step (321), if the time limit has not elapsed, the process returns from step (321) to step (312), and the steps after step (312) are executed again.

However, if the time limit has elapsed in step (321), the process proceeds from step (321) to step (323), and in this step (323),
A standby mode is set in which all channels are scanned to monitor reception, and each time one scan is completed, an operation of entering a sleep mode for 2.54 seconds, for example, is repeated. Further, in this standby mode, the setting is made such that, when a connection is made to the base unit (2) by calling or the like, the connection is made on any available channel. Thereafter, the handset (1) enters a standby mode for intermittent reception of all channels.

Therefore, in this case, the handset (1)
During standby, all channels are monitored for reception.

In this case, the period from the reception monitoring of an arbitrary channel to the reception monitoring of that channel again is 3.74 seconds (= 120 ms × 10 channels + 2.54 seconds). This is equal to 3.74 seconds (= 120 ms × 2 channels + 3.5 seconds) of the period of the original standby mode in which the reception monitoring is performed. Therefore, when a call is received, the time required for the base unit (2) to connect the handset (1) is on average equal. However, the sleep period is shortened from the original 3.5 seconds to 2.54 seconds.

Further, in step (315), step (414)
When the command signal CMND of the response by (3) cannot be received, the process proceeds from the step (315) to the step (322).
It is checked whether a predetermined time limit, for example, 41 seconds, has elapsed since the execution of step 12).

Then, in step (322), when the time limit has not elapsed, the process returns from step (322) to step (314), and the steps after step (314) are executed again.

However, when the time limit has elapsed in step (322), the process proceeds from step (322) to step (323), and in this step (323),
Set to standby mode for intermittent reception of all channels,
Thereafter, the operation enters the standby mode.

Further, also in the base unit (2), in step (413), when the command signal CMND of the data EMCH of the vacant channel in step (314) cannot be received, the processing is performed from step (413) to step (421).
And proceeds to step (421).
2) After the first execution, a predetermined time limit, for example, 41
It is checked whether or not seconds have elapsed. If the time limit has not elapsed, the process returns from step (421) to step (412), and the steps after step (412) are executed again.

However, if the time limit has elapsed in step (421), the process proceeds from step (421) to step (422), and in this step (422)
A standby mode for scanning all channels and monitoring reception is set. Further, in this standby mode, the setting is made such that when connecting to the handset (1) by an incoming call or the like, the connection is made on any available channel. Thereafter, the operation enters a standby mode for receiving all channels.

Further, in step (415), when the command signal CMND in step (316) of the handset (1) cannot be received, the processing proceeds from step (415) to step (421).

H Effects of the Invention Thus, according to the present invention, the handset (1)
And when the base unit (2) is connected, only two channels indicated by the channel data CHDT registered in the RAMs (142) and (242) can be used for this connection. , Automatically updated at the end of the call.

Therefore, even if only two channels are monitored by the handset (1) during standby, the permitted ten channels can be used effectively. At the time of an incoming call, the base unit (2) communicates with the handset (1). The channel can be reliably opened in between.

Further, since it is not necessary to shorten the sleep mode period of the handset (1) during standby, the consumption of the battery (151) during standby does not increase.

Further, even in a cordless telephone in which a microphone and a speaker are provided in the base unit (2) so that an extension call can be made between the base unit (2) and the handset (1), the extension call can be reliably realized.

[Brief description of the drawings]

1 and 2 are flowcharts showing an example of the present invention, FIG. 3 is a protocol diagram thereof, FIG. 4 is a system diagram thereof, and FIGS.
FIG. 10 is a diagram for explaining this. (1) is a handset, (2) is a base unit, (11)
0) and (210) are transmission circuits, (120) and (220) are reception circuits, and (300) and (400) are processing routines.

Claims (1)

(57) [Claims] The base unit and the handset store n (m is a plurality of smaller) m channels of the m (m is a plurality) communication channels, and the base unit is configured to store the m (m is a plurality of m) smaller channels during standby. And the handset monitors the n channels, and the base unit and the handset connect via any one of the n channels during a call. The base unit stores a free channel among the m communication channels during standby, and performs a call between the base unit and the handset via the one channel during standby. When the processing is completed, the base unit sets the n channels as described above. Examined whether or not included in the free channels that are,
When not included, the abnormality information and the information of the stored empty channel are transmitted to the handset. When the handset receives the abnormality information and the information of the stored empty channel, the handset transmits the m communication channels. Is monitored to detect an empty channel, the detected empty channel is compared with the stored empty channel to check for an overlapping empty channel, and n empty channels are selected from the overlapping empty channels. Selecting, transmitting information on the selected n available channels to the base unit, and storing the stored n
The base unit stores the selected n available channels transmitted from the handset instead of the stored n channels. Call method.