JPH02119438A - Cordless telephone set - Google Patents

Abstract

PURPOSE:To attain simultaneous call in a short time by adopting the processing such that a data representing simultaneous call is sent to a slave set selected as a representative through a control channel a speech channel is opened with the slave set selected when a reply is obtained from the slave set. CONSTITUTION:A transmission circuit 110 in the 1st-8th handsets 1A-1H converts a voice signal St and a command signal CMND into an FM signal Su of an incoming channel and sends the result, and a reception circuit 120 receives an FM signal Sd of an outgoing channel and demodulates a voice signal Sr and the command signal CMND. In the case of simultaneous call of the handsets 1A-1H, a representative handset ais selected and the representative handset is called and the reply from the representative handset is awaited, and when no reply exists, the representative handset is selected newly to apply the similar processing. Thus, a channel is opened in a short time.

Description

[Detailed description of the invention] The explanation will be given in the following order.

A. Industrial application field B. Summary of the invention C Conventional technology D Problems to be solved by the invention E. Means to solve the problem (Figure 1) F. Effect G Example G1 First embodiment (Figs. 1 to 8) H Effects of the invention A. Industrial application field This invention relates to a cordless phone.

B. Summary of the Invention The present invention is a multi-cordless telephone that allows simultaneous calling in a short time by performing calling processing on a plurality of handsets in a predetermined sequence.

C. Conventional Technology A low-power type cordless telephone uses the MCA system, and has 87 communication channels and 2 control channels.

Therefore, as an expanded version of the functions or capabilities of such a cordless telephone, for example, as shown in Fig. 9,
A so-called multi-cordless telephone is being considered in which a single base unit can be used in combination with a plurality of presets.

In other words, the figure shows a case where up to 8 slave units can be used.
(IA) to (IH) are handsets (handsets), (2)
indicates the base station, (3) indicates the telephone line, any handset and base station (2)
Radio waves are connected by the power of the handset, and a call is made between the handset and the person in question.

By the way, in such a multi-cordless telephone, for example, when a call arrives, the base station (2) calls all handsets (IA) to (IH) at the same time. Three methods are possible.

■ Call handset) (IA) to (1N) one by one, and after this call is completed, hand cent (1^
) to (IH).

■ Ring all handsets (IA) to (IH) at the same time and any /% handset will answer this call.

■ All hand cents (IA) to (IH) at the same time
This call is answered by a predetermined specific handset (hereinafter referred to as "one representative handset").

D. Problem to be solved by the invention However, with the method (■), calling takes time.

That is, since the handset IH (IA) to (IH) naturally operate using a battery (generally a rechargeable battery) as a power source, it is necessary to reduce current consumption as much as possible. So, the actual hand safety) (IA) ~
In (IH), as shown by the solid line in Figure 10A,
For example, every 2 seconds it enters the receive mode for 0.2 seconds and performs only the receiving operation, and for the remaining 1.8 seconds it enters the sleep mode (power down mode). All power is turned off except for the Note that each handset (IA) to (IH) is in reception mode for 0.2 seconds,
A) to (IH) are not synchronized, but are disjointed.

Then, at an arbitrary time t1, the base station (2
) needs to call the handset (LA), for example, the base station (2) sends the handset (IA) call signal as a command signal for, for example, 2.5 seconds, as shown in the same figure. Repeat the operation many times and send. Note that the length of one call signal is, for example, 120 msec, and is transmitted through a downlink control channel.

And like this, base station (2) is 2.5
If you send a ringing signal repeatedly for several seconds,
During that 2.5 seconds, the handset (LA) is always in the receiving mode at least once, so it will receive the call signal at time t2, for example.

Therefore, when the handset (IA) receives a calling signal at time t2, A! :6! J, as shown by the line, the reception mode continues after that, and the call signal from the base station (2) is received at time t.

As shown in C in the figure, at time t3,
A response signal indicating that the paging signal has been received is transmitted to the base unit (2) through the uplink control channel.

After that, predetermined processing is performed and the handset (I
A communication channel is opened between A) and the base station (2).

However, in the MCA cordless telephone, the control channels are Handsef) (IA) to (IH).
It can only be used to establish a communication channel between the control channel and the base unit (2), and the use of the control channel for other purposes is prohibited.

Therefore, when calling all at once using the method of A response is received on the uplink control channel, a communication channel is opened to one of the handsets that responded, and that handset rings.

As mentioned above, it takes 2.5 seconds (period t1 to t3) just to call one handset, so in the method (■), eight handsets (LA) to
(IH) is called up one by one in 20 seconds (=2
．． 5 seconds x 8 units), which is not practical.

On that point, in method (■), the handset (IA) ~
If even one of the handsets (IH) responds, a communication channel is subsequently opened between the responding handset and the base station (2), and it does not take a long time as in method (2).

However, with this method (■), the handset (IA) ~ (
Two or more of the IHs) may transmit response signals at the same time at time t, which causes interference and prevents the base station (2) from correctly receiving the response signals. 2) may not be able to open a call channel.

In addition, in the method of ■, the base station (2)
In response to the call, only the handset sends a response signal to the representative at time t3, so ■.

This method does not cause problems like the method (2).

However, with this method (■), when the representative handset is unable to receive a call signal from the base station (2), for example, when the battery voltage of the representative handset is low, or when the representative handset is malfunctioning, When another cordless telephone is using the control channel in the area where the representative handset is located, or when the representative handset is out of range, the call processing causes the representative to receive an answer signal from the handset. It stops at a step.

This invention attempts to solve the above problems.

E. Means for Solving the Problems Therefore, in this invention, - at the time of simultaneous calling,
First, the representative handset is called, and if there is a response signal, a communication channel is opened with the representative handset, but if no response signal is obtained, another handset is designated as the representative handset, and the same process is performed thereafter. It was designed to be repeated.

F. Even if there are handsets that do not respond, the system will not go down and a call will be made in a short time.

G. Embodiment In the example shown in FIG. 1, there are two outside lines, up to eight slave units can be supported, and only one control channel is used.

In the figure, (IA) to (Ill) indicate first to eighth handsets. These handsets (IA) ~ (I
H) have the same configuration, so the handset (1
To explain this on behalf of a person, (IN?) is a transmitting circuit, and (120) is a receiving circuit. Then, the transmitter circuit (110) sends the audio signal St and the command signal ('HD (details will be described later) to the F of the upstream channel.
It changes to the M signal Su- and transmits it, and the receiving circuit (t2o>,

receives the FM signal Sd of the downlink channel and demodulates the audio signal Sr and command signal CMNO.

Also, (,131) is a dial key, (132)
is a talk key, and this talk key (132) is a non-locking type button switch, and this key (
132) Each time you press , the handset (one person) toggles between standby mode and talk mode. Then, when in standby mode, the handset (IA) alternately repeats reception mode and sleeve mode on the downlink control channel, as explained in FIG. 10, and when in talk mode, performs continuous reception and transmission. .

Furthermore, (133) to (137) are auxiliary keys such as extension keys configured with non-locking type bush switches, (139) is a ringer speaker,
(140) is a microcomputer for system control. In this microcomputer (140), a command signal CMND to be transmitted by a transmitting circuit (110) is formed, and a receiving circuit (140) generates a command signal CMND.
20) Command signal taken from CIA N
D is determined. In addition, the microcomputer (140) uses control signals TCTL and RCTL to enable/disable transmission of the transmitting circuit (110) and control the channels on which the transmitting circuit (110) and the receiving circuit (120) perform transmission and reception.
is also formed.

Furthermore, (141) is a RAM, and this RAM (1
41) stores a 25-bit system identification code 5YrD for identifying this multi-cordless telephone from other cordless telephones. Furthermore, the handsets (IA) to (IH) are provided with "1" to "1" in order to identify these handsets (LA) to (IH) from each other.
8" handset number is assigned (the order of assignment is arbitrary), and the handset number is assigned to the RA as a 4-bit handset identification code H3ID.
M (141). Note that when the identification code (handset number) H3ID is "0", all handsets (IA) to (IH) correspond.

Also, (2) is the base station, (3A), (
3B) indicates a telephone line (external line). Then, at base station (2), (21A) to (21C)
indicates a base unit, and these base units (
21A) ~(21C) is the handset (1^)~
(IH) transmitting circuit (110) and receiving circuit (1
20) Similar transmitter circuit (210) and receiver circuit (
220>. However, each receiving circuit (220) of these base units (21A) to (21C)
) to (220) are continuously in reception mode on the uplink control channel when not talking.

Furthermore, at the base station (2), (22)
(23^), (23B) are an outside line interface circuit, and (24) is a microcomputer for mask control. In this case, the switch circuit (22) is connected between the base units (21A) to (21C) and between the base units (21A) to (21C) and the interface circuits (23A) and (23B), depending on the purpose of communication. It connects. In addition, an interface circuit (23A),
(23B) is a 4-wire/2-wire conversion circuit (231)
A switch circuit (232>) corresponding to the hook switch of a general telephone, a dial tone signal (DTIA
F signal) forming circuit (233), ring tone signal detecting circuit (234), and the like.

Furthermore, the microcomputer (24) is connected to the handset (IA)
In addition to performing the same processing as the microcomputer (140) in (IH), the handsets (IA) to (IH),
Call channel, base unit (21A) ~ (2
IC), line (3A).

(3B) is used to manage the entire operation of this cordless telephone, such as the usage status. Further, (241) is a ROM, and a system identification code 5YID is written in this ROM (241).

FIG. 2 shows an example of the signal format of the command signal C:JNO. This signal CMNO has a 24-bit bit synchronization signal BSYN at the beginning, followed by a 16-bit frame synchronization signal FSY! It has l. in this case,
These signals BSYN, FSYN are e.g.
N = “101010・・・・・・・・・10″
FSYN="1100010011010110"・
...FSY for upstream channel! II = “1001001100110110
”...has a specific bit pattern indicated for the downstream channel.

Further, the command signal CMNO includes, in order, a 25-bit system identification code 5YID, a 12-bit error correction code ECC for this code 5YID, and a 3-bit dummy bit DBIT following the signal FSYN. A 5-byte control code CTRL follows DBIT.

In this case, the control code CTRL is its first byte CT
LI is a code indicating the control contents of the handset (IA) to (IH) and the base station (2), and the second
Byte CTL2 to fifth byte CTL5 are parameters or data related to the first byte CTLI.

Example Eva, the base station (2) is connected to the handset (I).
When notifying the channel number of a call channel to any of A) to (IH), CTLI: Code indicating that it is a call channel notification CTL2: Handset identification code of the other party's handset) IsID CTL3: Call Channel number CTL4.
CTL5: Considered a dummy. Note that in most cases, the second byte CTL2 is the handset identification code (ISrD) as described above.

Then, the handsets (IA) to (IH) or base units (21A) to (21C) receive this command signal C! , INO is received, the microcomputer (140) or (24) reads the identification code 5YID (and) included in the signal CMNO.
ISID) is the identification code 5 stored in your RAM (141) or ROM (241).
It is checked whether it matches YID (and H3ID), and only when it matches, the command signal CM
NO is considered valid, and when they do not match, it is invalidated.

[Make a call from the handset]

A call to an outside line from handseras (IA) to (IH) is made, for example, as shown in the connection sequence shown in FIG. That is, in the figure, vertical solid lines indicate channels used by the handset and base unit, C is a control channel, and ■ is a speech channel. Also, when the solid line indicating this channel is a single line, it is in sleeve mode (this is only for handsets), when it is a double line, it is in receive mode, and furthermore, the hatched period indicates that transmission is permitted. show.

For example, when the handset (IA) is in standby mode, when the talk key (132) is pressed, this is detected by the microcomputer (140), and the microcomputer (140) supplies a transmission control signal TCTL to the transmitting circuit (110). As a result, the transmitter circuit (1
10) and the receiving circuit (120) are enabled to transmit and receive on the control channel and set to talk mode, and the microcomputer (140) receives a command in which the control code CTRL indicates a call request and its handset identification code (ISID). A signal CλINO is formed and this signal CMNO is transmitted to the transmitting circuit (110).
supplied to

Therefore, in the transmitting circuit (110), the signal C
MNO is the FM signal of the uplink control channel (FSX
signal) Su, and this signal Su is transmitted to the antenna (
100) to the base station (2).

Then, in the base station (2), the signal (radio wave) Su is received by the antenna (200), and this received signal Su is transmitted to the base unit (2).
1^) to (21C) are supplied. In this case, for example, if the base unit (21A) is vacant, the receiving circuit (220) of the base unit (21A) is in the receiving mode of the uplink control channel, so this receiving circuit (220) is in the receiving mode of the uplink control channel. ) in FM
The command signal CyAN [+ is demodulated from the signal Su,
This signal CλINO is supplied to the microcomputer (24), and the identification code 5YID included in the signal CMNO is
241) is checked to see if it matches the identification code 5YID.

And in this case, along with matching, the handsera)
Since the call request is from the IA, the microcomputer (24) supplies the transmission control signal TCTL to the transmission circuit (210), which allows the transmission circuit (210) to transmit on the downlink control channel. The microcomputer (24) receives a command signal CM in which the control code CTRL indicates permission to make a call, the handset identification code H3ID, and the channel number of the communication channel.
N[+ is formed and supplied to the transmitter circuit (210).

Therefore, in the transmitting circuit (210) of the base unit (21A), the signal CMNO is converted into the FM signal Sd of the downlink control channel, and this signal Sd
is connected to the handset (IA) through the antenna (200).
) to (IH).

Then, in the handset (IA), FM is transmitted from the base station (2) through the downlink control channel.
When the signal Sd is transmitted, this antenna (100
) is received by the receiver circuit (120), and from the receiver circuit (120) is a command signal C1.
, I N [1 is taken out and the microcomputer (140)
supplied to

Then, the identification code 5YIS, HSID included in the command signal CIJND is transferred to the RAM (141).
Identification code stored in 5YIS, )ISI
D, the transmitting circuit (110) and the receiving circuit (120) receive the control signal TCTL.

Command signal C! received by RCTL! , I N
The communication channel is switched to the channel number indicated by the control signal CTRL in D.

In (21A), the command signal C! , the handset (IA
) to specify the call channel, the microcontroller (2)
4) to the transmitter circuit (210> and the receiver circuit (220)
Transmission control signal TCTL and reception control signal RCTL
is supplied to the transmitting circuit (210) and the receiving circuit (2
20) is switched to the communication channel of the channel number instructed by the microcomputer (24) to the handset (one person).

The power is the handset CIA) base unit)
This means that a communication channel has been opened between (21A) and (21A).

At this time, the remaining handsets (IB) to (IH)
, the FM signal Sd sent from the base station (2) is received, but the sent handset identification code H3ID does not match its own, so it remains in standby mode on the downlink control channel. be done.

Subsequently, in the handset (IA), a command signal CMND is formed in which the control code CTRL indicates that the switching to the speech channel has been completed, and this signal C!
A N D is the F of the switched call channel.
It is transmitted to the base station (2) by the M signal Su.

This FM signal Su is transmitted to the base station (21
A) When the command signal CMNO is received by the base unit ( 21A) is transmitted to the handset cell (LA) by the FM signal Sd of the switched communication channel.

Furthermore, in the base station (2), among the interface circuits (23A) and (23B),
In the case of the vacant interface circuit shown in the figure, the interface circuit (23A) is selected and its switch circuit (232) is turned on (off-hook state), and the switch circuit (22) is controlled to switch to the base unit) ( The transmission circuit (210) and reception circuit (220) of the interface circuit (21A) are connected to the conversion circuit (23A) of the interface circuit (23A) through the switch circuit (22).
231).

Therefore, the base unit (21A) includes the switch circuit (22) and the interface circuit (23A).
As a result, the handset (IA) is connected to the line (3^) through the circuit (21A), (
22), (23A) are connected to the circuit * (3A).

[Call]

Next, when the caller enters the telephone number of the other party using the dial key (131) of the handset (IA), the control code CTRL indicates that a telephone number is to be sent and a command signal CIJ N D indicating that the telephone number is to be sent. is formed, and this signal CIJ N D is transmitted to the communication channel F
It is converted into an M signal Su and transmitted.

Therefore, in the base station (2), the command signal CMNO is sent to the base unit (21A).
This signal C is obtained from the receiving circuit (220) of
! , I N D control code CTRL indicates that a telephone number is to be sent and indicates the telephone number, so the forming circuit (233) is controlled by the microcomputer (24) according to the telephone number and the hand cell l-(IA ) A dial tone signal corresponding to the telephone number sent from
A).

When the other party answers the phone, the voice signal Sr from the other party is sent to the base unit l-(21A) through the signal line of line (3A) → switch circuit (232) → conversion circuit (231) → switch circuit (22). is supplied to the transmission circuit (210). Therefore, the signal Sr is
It is converted into an FM signal Sd of the downlink communication channel, and this signal Sd is transmitted from the antenna (200).

This signal Sd is received by the handset (IA) and sent from the receiving circuit (120) to the audio signal Sr.
is extracted and this signal Sr is supplied to the receiver (121).

Furthermore, when transmitting a call, the audio signal St from the transmitter (111) is supplied to the transmitter circuit (110) and converted into the FM signal Su of the uplink communication channel, and this signal S
u is transmitted from the antenna (100) to the base station (2).

Then, in the base station (2), the signal Su is received by the base unit (21A) and the signal St is taken out from the receiving circuit (220), and this signal St is transmitted from the switch circuit (22) to the interface circuit (23A). converter circuit (231) → switch circuit (232) through the signal line (3A
) and sent to the other party's phone.

[End episode]

When the call ends, as shown in Figure 4, when the talk key (132) of the handset (IA) is pressed, the control code CTRL indicates the end of the call and the command signal CM indicates the handset identification code (IsID). N O is formed and this signal CMNO is transmitted to the base station (2) by means of the FM signal Su of the communication channel.

Then, the receiving circuit (220) of the base unit (21)
The command signal CMNO is extracted from the microcomputer (24), and the microcomputer (24) determines that the call is over. As a result, the transmitter circuit (210) of the base unit (21^)
The transmission of is prohibited by the control signal TCTL, and
The receiving circuit (220) is placed in an uplink control channel receiving mode by the control signal RCTL. In addition, the interface circuit (23A> switch circuit (232A)
) is also considered off (on-hook state).

Furthermore, in the handset (IA), after transmitting the command signal CM N O indicating the end of the call, the transmitting circuit (110
) is prohibited from transmitting by the control signal TCTL, and the receiving circuit (120) is placed in standby mode on the downlink control channel by the control signal RCTL.

[To the handset! Call) t = Incoming call from outside line to handset (IA) to (IH) is...
For example, the connection sequence shown in FIGS. 5 and 6 is performed by routines (700) and (800) in the flowcharts shown in FIGS. 7 and 8. However, the routine (TOO) is the RO of the microcomputer (24).
The routine (800) is written in the microcomputer (24) and executed by the microcomputer (24).
0) is written into the ROM (not shown) and executed by the microcomputer (140).

That is, for example, when a call is received through the line (3A), the ring tone signal is detected by the detection circuit (234>) of the interface circuit (23 people).
This detection signal is supplied to the microcomputer (24).

Then, the routine (700) is executed by the microcomputer (24).
is executed, and in step (701), a vacant base unit among the base units (21A) to (21C,), for example, the base unit) (
2LA) is selected, and then step (702)
At this time, the identification code HSID of a vacant handset among the handseras l-(LA) to (IH) is registered in the vacant handset table STB of the RAM (not shown) of the microcomputer (24).

However, in this case, for the handset that has opened a channel with the base station (2), when opening that channel, the identification code ll5ID of that handset can be known, so the channel can be opened. The handset is an empty handset table)
For handsets that are not registered with ISTB but remain, even if they are unable to open a channel due to low battery voltage, malfunction, or being out of range, the microcontroller (24) will not be able to open the channel. Since the handsets cannot be identified, such handsets are also registered in the ISTB table.

Subsequently, in step (711), it is checked whether the table 115TB is empty, and if it is empty, the process proceeds to step (718), and in this step (71B), the oscillation circuit (242) is activated by the microcomputer (24). ) is driven to the speaker (
243) will sound an alarm and inform you that there is an incoming call but no handset is available.

Then, in step (711), table H
If the STB is not empty, the process proceeds to step (712).
The process proceeds to Step 1, and one of the handsets registered in the table HSTB, for example, handset (18), is selected as the representative handset.

Then, in step (713), the control code CTRL indicates that there is an incoming call, the identification code H5ID of the representative handset (in this case, the handset (IA)), the channel number of the call channel, and the simultaneous arrival. A command signal CM circle indicating that it is a call is formed, and this signal CMNO is passed through step (701).
), in this case, the base unit (2LA), transmits through the downlink control channel. Note that this signal CM N D is repeatedly transmitted for 2.5 seconds (period 1+-13 in FIG. 10).

Then, the transmission of the signal CMNO is finished (at the time tz)
, steps (714) to (716), in the base unit (21A), the uplink control channel is monitored for a predetermined period T, and a command signal CM indicating an incoming call response from the handset (IA) (representative handset) is output. The presence of NO is checked.

Then, when a command signal CMNO for incoming call response is received from the representative handset (IA) within period T1,
Processing is from step (715) to step (721)
Proceed to. Further, the connection sequence will be the one shown in FIG. 5 from now on.

Then, in step (721>), the channel of the base unit (21A) is switched from the control channel to the communication channel instructed in step (713).Subsequently, steps (722) to (
724), in the base unit (21A), the communication channel switched in step (721) is monitored for a predetermined period T2, and the control code CTRL is sent from the representative handset (IA) as a command signal C! indicating completion of channel switching. JN
It is checked whether O has been sent. Then, a command signal CIA N indicating the completion of channel switching is sent.
When D is not transmitted within the period T2, the base unit (21A)
is reset to the original standby state and ends this routine (700), but when the command signal CMNO indicating completion of channel switching is transmitted within period T2, in step (731),
Command signal CM N whose control code CTRL indicates a response
O is sent over the speech channel.

Then, in step (732), the switch circuit (22) is controlled by the microcomputer (24), and the transmission circuit (210) of the base unit (21A) is controlled by the microcomputer (24).
and the receiving circuit (200) are connected to the conversion circuit (231) of the interface circuit (23A) through the switch circuit (22), and the switch circuit (22) is connected to the conversion circuit (231) of the interface circuit (23A).
232) is turned on.

Therefore, the base unit (21^) is connected to the line (3^) through the switch circuit (22) and the interface circuit (23A).

On the other hand, in steps (715) and (716), the period T.

When the command signal CMNO in response to the call cannot be received from the representative handsera (LA), the process proceeds from step (716) to step (717).

Further, the connection sequence will be that shown in FIG. 6 from now on.

That is, within period T1, the representative handset (IA)
If there is no response to the incoming call, in step (717), the identification code H3ID of the handset that has been selected as the representative handset (in this case, the handset) (IA) is deleted from the vacant handset table H3TB, and the next Then the process returns to step (711).

Therefore, from now on, the next available handset, for example, handset (IB), is selected as the representative handset, and the above-described process is performed on this handset (IB).

Therefore, according to steps (711) to (717), when a call arrives, one of all available handsets is selected as the representative handset, and the representative handset is notified of the incoming call. The representative handset is sequentially switched until an incoming call response is obtained from the representative handset. Then, if there is an incoming call response from the representative handset, step (721)
~ (732) Processing for a telephone call is performed.

For such processing of base station (2),
The following processing is performed in the handsets (1^) to (IH).

That is, among the handsets (IA) to (IH), all handsets in standby mode (excluding handsets with low battery voltage, etc.) have their receiving circuits (120) in the same state as explained in FIG. A reception operation is performed intermittently, and when this reception operation starts, a routine (800) is executed.

That is, at time t2 (the absolute time of this time t2 differs depending on the handset), the microcomputer (140
) and the receiving circuit (120) start up from the sleeve mode, and in step (801) it is checked whether the carrier signal (FM signal Sd) can be received on the downlink control channel, and if it cannot be received, the microcomputer (140) and receiving circuit (120)
enters the standby mode (sleeve mode) again and ends this routine (800), but when the carrier signal can be received, the reception is continued in step (802), and then in step (803), the reception is continued. The signal is the step (713)
Command signal C with control code CTRL indicating incoming call by
It is checked whether it is an MNO, and if it does not indicate an incoming call, the microcomputer (140) and the receiving circuit (1
20) also enters the standby mode, sleep mode, and ends this routine (800).

However, if the signal received in steps (801) and (802) is the command signal CMNO transmitted in step (713), the control code CTRL of that signal CMNO indicates an incoming call, so processing is not performed. goes to step (804) and this step (804)
, a time wait is performed until time t3 when the transmission of the FM signal Sd ends, and at time t, step (811) is performed.
In step (713), the command signal C! , 4 NO, it is checked whether the identification code H3ID indicating the representative handset matches the identification code H3ID of the user himself, that is, whether he is designated as the representative handset.

Then, in the handset designated as the representative handset, the process proceeds from step (811) to step (812), and in this step (812), transmission of the FM signal Su is permitted, and
The command signal C! indicates that the control code CTRL is an incoming call response and the handset identification code (ISID). J
N D is formed and this signal CM N O is sent to the pace station (2) through the upstream control channel.

If this incoming call response is made within the period T1, the command signal CIA N D is determined in step (715) as described above.

Next, the processing of the microcomputer (140) is performed in step (8).
H), in this step (813) the channel is specified by step (713),
Then, in steps (801) and (802), the communication channel is switched to the one indicated by the command signal CMNO received, and then in step (814), a command signal CMNO is formed in which the control code CTRL indicates completion of channel switching. Sent through the uplink communication channel.

Note that this channel switching completion command signal CM
N[1 is determined by step (723).

Subsequently, in steps (821) to (823), the speech channel switched in step (813) is monitored for a predetermined period T, and a response command signal C'MNO is output in step (731).
The signal is checked and the response command signal C! J
When ND is received within the period T3, the process proceeds from step (822) to step (824), and in this step (824), the microcomputer (140)
The oscillation circuit (138) is controlled by the oscillator circuit (138) to form a ringer signal, and this signal is supplied to the speaker (139), which produces a bell sound indicating an incoming call.

Therefore, when the user of the handset (IA) presses the talk key (132), the ringer signal of the oscillation circuit (13B) is turned off and the bell sound is stopped, and then the transmission circuit (110) is turned off by the control signal TCTL. Transmission on the uplink control channel is permitted.

Therefore, from now on, it is possible to make a telephone call between the handset operator (LA) and the other party.

Note that if the response command signal CMNO is not received within the period T3, the process exits step (823) and enters the standby mode (sleeve mode).
,-, General handsets also perform step (713>
Command signal INO and step (801) ~
(804), the handset wakes up from the sleeve mode and enters the receiving mode. However, in these general handsets, the processing proceeds from step (811) to step (831), and receives data on the control channel for a predetermined period T. After continuing the mode, enter standby mode, sleeve mode.

[Extension call]

This is a call between any two handsets (IA) to (IH), and is performed as follows.

That is, for example, when the handsera (LA) is in standby mode, the auxiliary keys (133) to (137)
), then press the number key (131) corresponding to the handset number of the handset you wish to make an extension call to (this is equal to the handset identification code H3ID). The control code CTRL is the key (133) ~
(137) was pressed, the pressed key was the extension key (133), and the number key behind the dial key (131) was pressed (recipient's handset identification" - HDIS). and a command signal CIA indicating the own hand cent identification code 11sID.
ND is formed, and this command signal CM ND is transmitted to the base station (2) by the F N1 signal Su of the upstream control channel.

For example, if the base unit (21A) is vacant, this base unit (21A>9)
The command signal CMNO is taken out from the N circuit (220), and it is determined that it is a request for an extension call from the handset (IA).From then on, the handset (IA) and base unit (21A) are )
The A tongue channel is opened.

Furthermore, in the base station (2), the microcomputer (24) selects an available base unit and an available communication channel.
If (21B) is vacant, the FM signal Sd of the command signal CM NO is transmitted by this base unit (21B) through the downlink control channel. However, at this time, the command signal CM'
The control code CTRL in ID is data indicating that it is an extension call, the hand center identification code H3ID of the party with whom the handset (1^) desires to make an extension call, and the channel number of the call channel.

And this command signal C! ,'l N D's FM signal Sd is sent to the handset of the desired partner of ('1.A), such as a handset) (III)
When the call is received, a bell will sound from the handset (IH) speaker (139) in the same way as for an incoming call, and the other party will press the handset (IH) talk key (139).
31) Press to open a communication channel between the handset (IH) and the base unit (21B).

In addition, since the base station (2) is an extension call, the switch circuit (22) is controlled by the microcomputer (24).
is controlled, and the transmitting circuit (210) and receiving circuit (220) of the base unit (2iA) are connected to the base unit (21B) through the switch circuit (22).
It is connected to the receiving circuit (220) and the transmitting circuit (210).

Therefore, the handset (IA) is connected to the handset (IH) through the base station (2),
Thereafter, extension calls can be made between the handset (IA) and (IH).

Then, end the call, handset) (LA), (
ll.

On the other hand, for example, the handset (IA) is connected to the talk key (1
31), the handset (18) and base unit (21A) are pressed in the same way as when ending a call with an outside line.
), the call is terminated and these are placed in standby mode. Also, from the base unit (21B) to the handset controller (III), the control code CTRL indicates the end of the call and the identification code HSI of the handset (IH).
A command signal CMN[l indicating D is sent, and the handset (IH) and base unit) (21B) also perform call termination processing and enter standby mode.

[Other operations]

Similar protocols can also be used to transfer an outside line from one handset to another, to make a royal call between an outside line and two handsets, or to ring all remaining handsets from one handset. .

Note that in the above description, if step (713) is executed once, the free handset is used for period T.

Since the control channel is in reception mode for the entire period, in step (713), a command signal CM indicating an incoming call is sent to the second and subsequent representative handsets.
When sending NO, it can be sent once or several times.

Effects of the Invention H As described above, according to this invention, it is possible to simultaneously call a plurality of handsets (IA) to (IH). In this case, in particular, according to this invention, the handset When making a simultaneous call of (IA) to (IH), select a representative handset, call the representative handset, wait for a response from the representative handset, and if there is no response, select the representative handset again. If you have a handset that can open a channel, you can open the channel in a short time instead of requiring 20 seconds as in the case of method ①. can be opened. Moreover, the control channel is then only used as specified.

Furthermore, as in the case of the method (2), there is no possibility that a plurality of handsets simultaneously respond to a simultaneous call, causing interference, and therefore the channel can be reliably opened.

Furthermore, even if there is a handset that cannot open the channel, as in the case of method (2), the processing does not stop due to access by that handset.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an example of the present invention, and FIGS. 2 to 10 are diagrams for explaining the same. (IA) to (IH) are handsets, (2) is a base station, (110) and (210) are transmitting circuits, and (120) and (220) are receiving circuits. Figure 2 End of story Figure 4 1H1 (I8) +IA) (21A1 Huifun peak arrival Sokezosu Figure 5 Han kt Doo X-Suuniu F Call to fire Zokesos Figure 3 Han) Mine Zokeso λ Fig. 8 IA-vjH Hunt ° Death Vt 2X- Susteso 1 So Fig. 10

Claims (1)

[Claims] When a plurality of slave units and a base unit are used in combination, and when a communication channel is opened between the slave unit and the base unit, a control channel is transmitted from the base unit to the slave unit. data specifying the call channel is transmitted through the MCA, and the call channel is opened between the slave unit and the base unit based on the transmitted data.
In this type of cordless telephone, when the base unit performs a simultaneous call to the handsets, it selects one of the handsets as a representative, and sends data indicating the simultaneous call to the handsets selected as the representative through the control channel. If a response is not received from the handset selected as the representative, one of the remaining handsets is selected as the representative, and the above process is repeated until a response is obtained from the handset selected as the representative. Sometimes, the cordless telephone performs processing to open the above communication channel with the handset selected as the representative.