JPH0847046A - Digital cordless telephone set - Google Patents

Abstract

PURPOSE:To attain radio connection even when a radio wave does not reach a caller side and a callee side. CONSTITUTION:A relay slave set C stores a calling message from a master set A to a memory 4 tentatively and sends a link CH setup request message to the master set A, which is used for the relay station and when no reply comes from a slave set B, the master set A transmits a telephone answering call request message to the slave set C when no reply comes from a slave set B. Then the slave set transmits the calling message stored tentatively in the memory 4 in response to the telephone answering call request message in a prescribed timing and the message from the slave set B and the message from the master set A are stored tentatively in the memory 4 and sent respectively in a prescribed timing, then the radio connection between the master set A and the slave set B is conducted by using the slave set C as the relay station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone which can be directly wirelessly connected between a master unit and a slave unit and between a slave unit and a slave unit.

[0002]

2. Description of the Related Art Conventionally, a digital cordless telephone has a main unit (PS) connected to an exchange through a telephone line,
It is composed of a plurality of wireless slave units (CS), and as a wireless transmission / reception system between the master unit and the slave units, the TDMA / TDD system (Time
Division Multipie Access / Time Division Duplex)
The standards for such digital cordless telephones have been established at the "Radio System Development Center", and the final draft "RCR STD-2" has been adopted.
8 ”has been approved. And this standard "RCR
STD-28 ”specified by TDMA / TDD
In the method, one frame is composed of a plurality of transmission slots and the same number of reception slots, each reception slot is associated with each transmission slot, and transmission and reception are performed by a combination of the transmission slots and the reception slots. That is, since transmission and reception are temporally separated in the transmission slot and the reception slot, the transmission frequency and the reception frequency can be the same frequency, and a plurality of transmissions and receptions can be performed with one frequency. .

In such a digital cordless telephone, it is possible to make a wireless connection between the base unit and the handset and between the handset and the handset at a single frequency. It was carried out only within the reach of, and was equipped with an extension call function that allows direct calls by this single frequency wireless connection.

[0004]

However, in the above-mentioned conventional digital cordless telephone, it is necessary for both radio waves to reach in order to establish a wireless connection with a single frequency, and radio waves must be transmitted within a range where radio waves cannot reach each other. No connection could be made. Therefore, when making an extension call by using the extension call function, the range of calls that can be made by extension calls is the range within which the radio waves of both parties making the extension call can reach. There was a problem that extension calls could not be made between them.

It is an object of the present invention to provide a digital cordless telephone which can establish a wireless connection between a master unit and a slave unit and between slave units even when radio waves do not reach each other.

[0006]

In order to achieve the above object, the invention according to claim 1 is composed of a master unit and a plurality of slave units, and calls are made by differently transmitting and receiving. , And, in a digital cordless telephone that can directly talk between the master unit and the slave unit and between the slave units, when there is no response from the called side after transmitting the called signal for calling the called side, Calling means for making a call request to another station in the communication area, and, when receiving the call request to the call side, sends a call signal to call the call side to call the call side and the call side. And a relay means for relaying with.

According to a second aspect of the invention, the calling means is
An incoming call transmission means for transmitting an incoming call signal for calling the called side,
Judgment means for judging whether or not the called side responds to the called signal transmitted by the called transmission means, and sends a called side call request to another station in the communication area based on the judgment result by the judging means. And a call requesting means for the called side.

According to a third aspect of the invention, the relay means is
Incoming call receiving means for receiving an incoming call signal to the called side, information reading means for reading calling side information and called side information from the incoming call signal received by the incoming call receiving means, and the information reading means A notification means for notifying the calling side that the calling side is in the communication range based on the calling side information read by the calling side; and the information reading means in response to the called side calling request received after the notification by the notifying means. And a substitute call-in means for transmitting a call-in signal for calling the callee based on the callee information.

According to a fourth aspect of the invention, the relay means is
Temporary radio field intensity detection means for detecting the radio field intensity of the temporary response signal transmitted from the callee side in response to the call signal transmission, and detection signal transmission for transmitting the detection signal by the radio field intensity detection means to the calling side Means for receiving the detection signal, the signal strength detection means for detecting the signal strength of the detection signal, the signal strength detected by the signal strength detection means, the detection signal Other station selecting means for selecting another station to be used for relaying based on the radio field intensity based on the above.

According to a fifth aspect of the present invention, the relay means comprises:
The caller is provided with stop signal transmitting means for transmitting a relay stop signal to the caller and the callee when the caller and the callee cannot be relayed, and the caller is responsive to the relay stop signal. An incoming call signal for calling the called party is transmitted, and when there is no response from the called party after transmitting the called signal, the called party call request is made to another station in the communication area.

[0011]

Therefore, according to the inventions of claims 1 to 3, in order to establish a wireless connection between the master unit and the slave unit and between the slave units, the master unit or the calling side of the slave unit is connected. When calling a slave or master unit that is the called side and there is no response from the called side to the called signal transmitted from the calling side,
The call-in means determines that the call-in side is not within the communication range of the call-out side, and requests the call-in side to call the call-in side to another station in the communication range. Then, when the other station within the communication area of the calling side receives this called side calling request, the relay means transmits an incoming call signal for calling the called side to perform the relay between the calling side and the called side. As a result, it is possible to establish a wireless connection between the calling side and the called side.

According to the invention described in claim 4, when the relay means transmits an incoming call signal for calling the called side, and when a temporary response signal is sent from the called side in response to the incoming call signal, the temporary radio wave is transmitted. The strength detecting means detects the radio field strength of the temporary response signal received, and the detection signal transmitting means transmits the detection signal to the calling side. Then, when this detection signal is received at the calling side, the radio field intensity detection means detects the radio field intensity of the received detection signal, and the other station selection means is based on the radio field intensity and the detection signal detected by the radio field intensity detection means. By selecting another station to be used for relaying based on the radio field strength, an appropriate one can be selected as a relay station when there are a plurality of relay stations in the communication area of both the calling side and the receiving side.

According to the fifth aspect of the invention, when another station relaying between the calling side and the called side cannot perform the relay, the stop signal transmitting means relays to the calling side and the called side. Send a stop signal. When the call termination side receives the relay stop signal, the call termination means transmits the call termination signal to the call termination side, and when the call termination side does not respond to the call termination signal, the call termination side calls. When the other station that is relaying cannot perform the relay by making a call request to the called station to call the called party to another station that is within the communication area Also in the above, it is possible to establish a wireless connection between the calling side and the called side while newly setting another station as a relay station while maintaining the wireless connection.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a slave unit in a digital cordless telephone as an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an example of an arrangement state of a master unit and a slave unit of the digital cordless telephone, 3 is a control sequence diagram showing a basic operation of wireless connection in the relay operation, FIG. 4 is a control sequence diagram showing an operation of releasing the wireless in the relay operation, and FIG. 5 is another arrangement state of the master unit and the slave unit of the digital cordless telephone. FIG. 6 is a control sequence diagram showing a wireless connection operation including a relay station selecting operation in the relay operation, and FIG. 7 is a control sequence showing a wireless connection operation including a relay station switching operation in the relay operation. It is a sequence diagram.

In FIG. 1, 1 is an antenna for transmitting and receiving control signals and voice signals, 2 is a receiving system 2a switched at a set reception timing, and the signal received by the antenna 1 is modulated by π / 4 shift QPSK. Demodulation according to the method and at the transmission timing, the transmission system 2b
The radio unit 3 which modulates the transmission data input after being switched to the π / 4 shift QPSK and supplies the modulated data to the antenna 1 is decompressed by decompressing the signal demodulated by the reception system 2a of the radio unit 2. The signal processing unit analyzes the signal type, compresses the input digital data, adds an additional signal, creates a signal having a predetermined frame structure, and sends the signal to the transmission system 2b of the wireless unit 2.

Reference numeral 4 is a memory for temporarily storing the digital data processed by the receiving system 3b of the signal processing unit 3, and 5 is an analog of the digital data processed by the receiving system 3b of the signal processing unit 3. A voice codec unit that decodes the signal and samples the input analog voice to convert it into digital data, 6 is a speaker that emits the voice message decoded by the voice codec unit 7, and 7 is a voice message that is an analog voice. It is a microphone that is input to the codec unit 5.

Reference numeral 8 denotes a secondary battery that serves as a power source for the device, 9 denotes a power source unit that supplies the voltage from the secondary battery 8 to each unit as a power source,
Reference numeral 10 is a battery remaining amount detection unit that detects the remaining battery amount of the secondary battery 8, and 11 is a charge detection unit that detects whether the secondary battery 8 is being charged.

Reference numeral 12 is a numeric keypad used for inputting a telephone number,
An operation input unit 13 including an outside call button, an extension call button, a relay function necessity switch, and the like, 13 is an operation input unit 12
It is a control unit that controls each unit based on an operation command from.

In the case where the master unit and the slave unit of the digital cordless telephone configured as described above are arranged as shown in FIG. 2, the master unit A calls the slave unit B to make an extension call between the master unit and the slave unit. The case of performing will be described based on the control sequence shown in FIG.

In FIG. 2, the broken line a indicates the radio wave arrival range of the master unit A, the broken line b indicates the radio wave arrival range of the slave unit B, the broken line c indicates the radio wave arrival range of the slave unit C, respectively. Machine C
Is located, the child device C is located within the broken line b, and the parent device A and the child device B are located within the broken line c. That is, base unit A
And the child device B cannot receive each other's radio waves, and both the parent device A and the child device B can receive the radio wave from the child device C.

In the arrangement of the master unit A and the slave units B and C, when the extension button of the operation input unit 12 of the master unit A is operated to make an extension call request with the slave unit B, the control unit 13 The signal processing unit 3 is controlled based on the operation command, and 29 bit
42-bit caller identification code (CS-ID) composed of the system call code and the 13-bit additional ID, and 2
28 bits composed of a PS calling code of 8 bits
A ringing signal including the destination identification code (PS-ID) is created in a predetermined signal format. The PS-ID included in the calling signal is ID information of the child device B.

Then, the calling signal created by the control unit 13 and the signal processing unit 3 is sent to the transmission system 2b of the radio unit 2, and the transmission system 2b of the radio unit 2 is controlled by the control unit 13 under the control of the signal processing unit. The incoming call message created in 3 is sent to the antenna 1 at a predetermined transmission timing, and is transmitted from the antenna 1 to the handset B (a1).

When the incoming message from the parent device A is received by the child device B by the receiving system 2a of the antenna 1 and the wireless unit 2, the receiving system 3a of the signal processing unit 3 performs predetermined signal processing on the incoming message. It is determined to be a call message, and the control unit 13 determines that the call is to the local station based on the calling identification code (CS-ID) and the receiving identification code (PS-ID) included in the incoming message. And this CS-
Using the ID, the transmission system 3b of the signal processing unit 3 creates a link CH establishment request message including the destination identification code (CS-ID) and the originating identification code (PS-ID) in a predetermined signal format, and the wireless unit The transmission system 2b of 2 and the antenna 1 transmit to the master unit A at a predetermined timing.

However, as shown in FIG. 2, the incoming call message from the master unit A cannot be received by the slave unit B from the radio wave coverage of the master unit A and the slave unit B in this embodiment, and the link CH No establishment request message or the like is transmitted to the master unit A.

On the other hand, the child device C within the radio wave arrival range of the parent device A
Then, the incoming call message transmitted to handset B is received. Then, when the incoming call message transmitted from the parent device A to the child device B in the child device C is received by the receiving system 2a of the antenna 1 and the radio unit 2, the receiving system 3a of the signal processing unit 3 of the child device C receives. It is determined that the incoming call message has been subjected to predetermined signal processing, and the control unit 13 calls the slave device B by the parent device A from the CS-ID and PS-ID included in the incoming message, that is, It is determined that the call is not to the station and the receiving system 3a of the signal processing unit 3
The incoming call message that has been signal-processed by is temporarily stored in the memory 4. When the control unit 13 determines that the parent device A is calling the child device B instead of calling the own device, the child device C informs that the own device is within the communication range of the parent device A. Then, the link CH establishment request message for requesting the designation of the communication carrier is transmitted to the master unit A (a2). The link CH establishment request message contains the CS-ID as the destination identification code and the PS-ID of the handset C as the originating identification code.

When the parent device A receives the link CH establishment request message from the child device C in the state where the parent device A is transmitting the incoming call message to the child device B, the parent device A receives the link CH establishment request message. To the local station, the control unit 13 does not transmit the link CH allocation message to the local station and communicates with the local station based on the CS-ID and PS-ID included in the link CH establishment request message. It is determined to be possible, and it is set to be usable as a relay station.

When the base unit A is transmitting an incoming call message to the handset unit B and the base unit A is set to the handset unit C as a relay station, PS- contained in the call destination message is transmitted. When the link CH establishment request message or the like from the child device B corresponding to the ID is not received even after waiting for a predetermined time,
The control unit 13 determines that the handset B is not within the radio wave arrival range of the own station, and transmits a proxy call request message to the handset C to call the handset B (a3).

When the proxy call request message from the master unit A is received by the slave unit C, the control unit 13 causes the memory 4
The incoming call message temporarily stored in is read out, and the read out incoming message is subjected to predetermined signal processing in the transmission system 3b of the signal processing unit 3 to have a predetermined signal format. (A4).

Since the handset B is within the radio wave arrival range of the handset C, the incoming call message from the handset C is received. Then, when the incoming call message is received by the handset B, the control unit 13 causes the caller identification code (CS-ID) and the incoming call identification code (PS-I) included in the incoming call message.
D) and it is judged that it is a call to the own station, and this C
The transmission system 3b of the signal processing unit 3 uses the S-ID to create a link CH establishment request message in a predetermined signal format, and transmits the message at a predetermined transmission timing under the control of the control unit 13 (a5).

When the slave C receives the link CH establishment request message from the slave B, the receiving system 3a of the signal processing unit 3 performs predetermined signal processing and determines that the link CH establishment request message. The control unit 13 determines that the slave unit B is within the radio wave arrival range of its own station, and temporarily stores in the memory 4 the link CH establishment request message subjected to the signal processing by the reception system 3a of the signal processing unit 3. Then, the link CH establishment request message temporarily stored in the memory 4 is read at the timing determined by the control unit 13, and the read link CH establishment request message is subjected to predetermined signal processing in the transmission system 3b of the signal processing unit 3. Control unit 1 with a predetermined signal format
It is transmitted at a predetermined transmission timing based on the control of No. 3 (a6).

When the parent device A receives the link CH establishment request message from the child device C, the receiving system 3a of the signal processing unit 3 performs predetermined signal processing and determines that the link CH establishment request message. , The controller 13 selects two or more available slots on a single frequency in the communication carrier confirmed according to a predetermined carrier sense condition, and selects two available slots in the selected communication carrier. Master A-Child C
Between the slave unit B and the slave unit C, and controls the transmission system 3b of the signal processing unit 3 and the transmission system 2b of the wireless unit 2 to transmit the link CH allocation message from the antenna 1 (a7).

When the child device C receives the link CH assignment message from the parent device A, the receiving system 3a of the signal processing unit 3 performs predetermined signal processing, and the control unit 13
In this case, the physical channel (slot and frequency) used with the master unit A is confirmed, the physical channel used with the slave unit B is confirmed, and this link CH allocation message is temporarily stored in the memory 4. . Then, the link CH allocation message temporarily stored in the memory 4 is read and transmitted at the timing determined by the control unit 13 (a8), and at the same time, a synchronization burst is transmitted based on the physical channel confirmed by the control unit 13 for synchronization. Establish (a9).

When the slave B receives the link CH assignment message from the slave C, the reception system 3a of the signal processor 3 performs predetermined signal processing, and the controller 13
In (a9), the physical channel used with the slave C is confirmed and a synchronization burst is transmitted to establish synchronization (a9).

Next, SABM (Set Asynchronous)
Nous Balanced Mode) (a10), this SAB
Upon receiving the M, the child device C transmits this SABM to the child device B (a11). Then, when SABMs are received by the slaves B and C, the UAs corresponding to the SABMs are received.
Return (Unnumbered Acknowledgment) to each (a
12).

After returning UA in the handset B,
The control unit 13 of the child device B determines that the link CH is established,
The transmission system 3b of the signal processing unit 3 and the transmission system 2b of the wireless unit 2 are controlled to transmit an incoming call response message from the antenna 1 (a13). When the handset C receives the call response message from the handset B, the handset C temporarily stores the call response message in the memory 4, and temporarily stores the call response message in the memory 4 at a timing determined by the control unit 13. The received call response message is read and transmitted (a14). And
When the master unit A receives the incoming call response message from the slave unit C, thereafter, the same message is transmitted / received as in the above by transmitting / receiving a predetermined message for setting various functions used for a call between the master unit A and the slave unit B. This is done by relaying machine C.

After various functions are set between the base unit A and the base unit B, a ringer (not shown) or the like is activated in the base unit B to notify the user of the base unit B to call. At the same time, the control unit 13 controls the transmission system 3b of the signal processing unit 3 and the transmission system 2b of the wireless unit 2 to transmit the call message (a15). When the handset C receives the call message from the handset B, the call message is temporarily stored in the memory 4, and the call message temporarily stored in the memory 4 is stored at the timing determined by the control unit 13. It is read and transmitted (a16).

When the user performs an on-hook operation by the operation input unit 12 in response to the call notification by the ringing of the handset B, the control unit 13 performs signal processing based on the on-hook operation by the operation input unit 12. Transmission system 3b of section 3
Also, the transmission system 2b of the wireless unit 2 is controlled to transmit the response message (a17). When the handset C receives the response message from handset B, the handset C stores the response message temporarily in the memory 4, and at the timing determined by the control unit 13, the response message temporarily stored in the memory 4 is sent. It is read and transmitted (a18).

When the master unit A receives the response message from the slave unit C, the control unit 13 responds to the received response message by the control unit 13 of the transmission system 3b of the signal processing unit 3.
Also, it controls the transmission system 2b of the radio unit 2 to transmit a response confirmation message (a19). When the child device C receives the response confirmation message from the parent device A, the response confirmation message is temporarily stored in the memory 4, and the control unit 1
The response confirmation message temporarily stored in the memory 4 is read and transmitted at the timing defined by 3 (a2
0).

Next, DISC (Disconnect) from base unit A
(A21), the slave C, which has received this DISC, transmits this DISC to the slave B (a22). When the handset B and handset C receive the DISC, the UA is returned to each of the DISCs (a
23), the master unit A and the slave unit C and the slave unit B and the slave unit C are in communication. Therefore, the master unit A and the slave unit B are in communication with each other by using the slave unit C as a relay station. In such a communication state, the voice data from the master unit A is transmitted by the physical channel between the master unit A and the slave unit C as in the case of the connection control of the communication channel, and temporarily the slave unit C. The audio data from the master unit A is transmitted by the physical channel between the slave unit C and the slave unit B stored in the memory 4 of the slave unit B.
And is emitted by the speaker 6. Note that the voice data from the slave unit B is also transmitted to the master unit A via the slave unit C in the same manner as above.
Be transmitted to.

Therefore, even when the slave unit B is not within the radio wave arrival range of the master unit A, the slave unit C serves as a relay station and the master unit A-
An extension call can be performed between the slaves B, and the voice data and the control message are relayed by the slave C and transmitted at different slot timings, and thus the slave C is relayed without causing radio wave interference with each other. As a station, it is possible to make a call between the master unit A and the slave unit B.

Next, the operation of terminating the extension call between the master unit A and the slave unit B using the slave unit C as a relay station as described above will be described based on the control sequence shown in FIG.

For example, when a call end operation is performed by the operation input unit 12 in the master unit A, the control unit 13 transmits a disconnection message based on the call end operation using the physical channel between the master unit A and the slave unit C. (B1), the handset C having received the disconnection message temporarily stores the disconnection message in the memory 4, and transmits the stored disconnection message using the physical channel between the handset B and the handset C. (B2).

When the disconnection message is received by the slaves B and C, the slave B uses the physical channel between the slave B and the slave C in response to the disconnection message, and the slave C receives the disconnection message. When a release message is returned to each of the physical channels between the master unit A and the slave unit C (b3), and the release message is received by the master unit A and the slave unit C, the master unit A responds to the release message. The physical channel between the master A and the slave C is used, and the slave C is the slave B-
The release completion message is transmitted using the physical channel between the slaves C (b4).

Next, the DISC is transmitted from the base unit A (b
5) The slave C, which has received this DISC, transmits this DISC to the slave B (b6). When the child devices B and C receive the DISC, the UA is returned to each corresponding to the DISC (b7).

Then, the wireless CH disconnection message is transmitted from the master unit A (b8), and the slave unit C which has received this wireless CH disconnection message transmits this wireless CH disconnection to the slave unit B (b9). When the handset B and handset C receive the wireless CH disconnection message, the wireless CH disconnection completion message is returned to each of the wireless CH disconnection messages (b10), and the communication is completed and the standby state is entered.

Next, the relay station selection control in the case where there are a plurality of child devices C which can be relay stations within the radio wave arrival range of the parent device A as shown in FIG. 5 will be explained based on the control sequence of FIG. To do. It is to be noted that the case where there are four slave units C that can be relay stations within the radio wave arrival range of the master unit A will be described, and the four slave units are the slave units C1, C2, and C2, respectively.
These are a child device C3 and a child device C4.

In the arrangement of the master unit A and the slave units B and C, when the extension button of the operation input unit 12 of the master unit is operated to make an extension call request with the slave unit B, the above-mentioned communication channel connection operation is performed. Similarly, the incoming call message is transmitted (c1).
Then, the child device C that receives the incoming call message from the parent device A
1, C2, C3 and C4 each judge that the call is not to their own station, store this incoming message in the memory 4 temporarily, and link CH to the master A.
The establishment request message is transmitted (c2).

Then, in a state where the base unit A is transmitting an incoming call message to the base unit B, the base units C1, C2,
When the link CH request message from C3 and C4 is received, the link CH is sent in response to the link establishment request message.
The control unit 13 sets that the slave units C1, C2, C3, and C4 can be used as relay stations without transmitting the assignment message. Then, in a state where the base unit A is transmitting an incoming call message to the handset unit B and the base unit A sets a plurality of handset units C1, C2, C3 and C4 as relay stations, When the link CH establishment request message or the like is not received from the corresponding slave unit B even after waiting for a predetermined time, the control unit 13 determines that the slave unit B is not within the radio wave coverage of its own station, and makes a proxy call for calling the slave unit B. The request message is transmitted to the respective slaves C1 to C4 at different timings (c3).

When the slave C1, C2, C3, and C4 receive the proxy call request message from the master A at individual timings, the temporary call is temporarily stored in the memory 4 based on the individually received timing. The incoming call messages stored in (4) are transmitted at different timings (c4). Then, when the slave B receives the incoming call message from each of the slaves C1 to C4 at different timings, the link CH establishment request message is transmitted at different timings based on the received timings (c5). . At this time, since the incoming call message from the handset C3 is not received by the handset B, the link CH establishment request message is not transmitted to the handset B.

Then, when the link CH establishment request messages from the handset B are received by the handset C1, C2 and C4 at individual timings, the receiving system 2 of the radio section 2 is received.
In a, the radio field intensity when the link CH establishment request message is received is measured, and the temporary response notification message including the measured radio field intensity information is provided at different timings based on the timing when the link CH establishment request message is received. Send (c6).

When the master unit A receives the temporary response notification messages from the slave units C1, C2, and C4 at individual timings, the reception system 2a of the wireless unit 2 receives the temporary response notification messages. The radio field intensity is measured and sent to the control unit 13, and the control unit 13
In, the radio field intensity information included in the temporary response notification message is read, and the radio field intensity information included in the temporary response notification message and the radio field intensity information when the temporary response notification message is received are stored in association with each other. And the child devices C1 and C
2 and C4, the temporary response notification message is received, the radio field intensity information is stored, and after the predetermined time has elapsed, when the temporary response notification message from the handset C3 is not received,
It is determined that the slave B is not within the radio wave arrival range of the slave C3, and which of the slaves C1, C2 and C4 is to be used as a relay station is determined.

The determination of the relay station is made based on the radio field intensity information stored correspondingly to the slave units C1, C2 and C4, and the link CH is established from the slave unit B in the slave units C1, C2 and C4. The signal strength at the time of receiving the message and the slave units C1, C2 and C in the master unit A
If the reception strength when the temporary response notification message is received from 4 is almost the same, and there are a plurality of similar reception strengths, the one having the strongest radio field strength is selected. According to the selection rule based on the radio field intensity information, the child device C2 which is considered to be located exactly in the middle between the parent device A and the child device B.
Will be selected as the relay station.

When the use of the child device C2 as the relay station in the parent device A is selected, thereafter, processing such as link CH allocation (c7, c8) is performed in the same operation as the above communication channel connection control, and finally. Assume communication.

Therefore, even when there is no child device B in the radio wave arrival range of the parent device A and there are a plurality of child devices that can be used as relay stations, the most suitable child to be used as a relay station. It is possible to make an extension call between the base unit A and the base unit B by selecting the base unit and using the selected base unit as a relay station.

Next, since there is no child device B in the radio wave arrival range of the parent device A, child devices C1 and C which can be used as a relay station are provided.
2 is in the range of the radio wave of the master unit A, and the slave unit C
1 is used as a relay station and an extension call is being made between the master unit A and the slave unit B, the slave unit C1 relays between the master unit A and the slave unit B due to insufficient battery capacity or deterioration of radio wave intensity. The call connection switching control when it becomes impossible will be described based on the control sequence of FIG. 7.

During communication between the master unit A and the slave unit B with the slave unit C1 as a relay station, the slave unit C1 cannot perform relay between the master unit A and the slave unit B due to insufficient battery capacity, deterioration of radio wave intensity, or the like. When it is determined that the slave unit C1 and the base unit A and the slave unit B
A relay stop notification message is transmitted at different timings (d1, d2).

When the master device A receives the relay stop notification message from the slave device C1, it transmits an incoming call signal for calling the slave device B at a timing different from the timing used for communication with the slave device C1 ( d3). When the child device B receives the relay stop notification message from the child device C1, it keeps the synchronization with the child device C1 and establishes an incoming call waiting state while communicating.

On the other hand, when the handset device C2 receives the incoming call message from the parent device A, it judges that the incoming call message is not a call to its own station, and the incoming call message is temporarily stored in the memory 4. , And transmits a link CH establishment request message to the base unit A (d4).

When the parent device A receives the link CH request message from each child device C2 while transmitting the incoming call message to the child device B, the link CH is assigned to the link establishment request message. The control unit 13 sets that the slave C2 can be used as a relay station without transmitting a message. Then, the parent device A is transmitting an incoming call message to the child device B, and the parent device A
When the slave C2 is set as a relay station and the link CH establishment request message or the like corresponding to the incoming call message is not received even after waiting for a predetermined time, the control unit 13 determines that the slave B is its own station. It is determined that the device is not within the radio wave arrival range, and a proxy call request message for calling the child device B is transmitted to the child device C2 (d5).

When the handset C2 receives the proxy call request message from the base A, it reads the incoming call message temporarily stored in the memory 4 and transmits it at a predetermined timing (d6). Then, in the child device B, the child device C
When receiving the incoming call message from 2, the link CH establishment request message is transmitted at a predetermined timing (d7),
The slave C2 relays the link CH establishment request message from the slave B (d8), and the master A receives the link CH establishment request message.

The base unit A selects one having two or more usable slots on the single frequency in the communication carrier confirmed in accordance with the predetermined carrier sense condition in response to the link CH establishment request message from the base unit C2. , The two usable slots in the selected communication carrier are designated between the master unit A and the slave unit C and between the slave unit B and the slave unit C2, and are transmitted as a link CH allocation message (d9).

When the handset C2 receives the link CH assignment message from the base A, the handset A-handset C and handset B are received from the received link CH assignment message.
-Confirm the physical channel used between the child devices C and temporarily store this link CH assignment message in the memory 4 and transmit it at a predetermined timing (d10). Then, synchronization bursts are transmitted on the physical channels based on the link CH assignment messages received by the slave C2 and the slave B, respectively, and synchronization is established (d11).
At this time, the synchronization burst is also transmitted from the child device C1 at a predetermined timing, but since the parent device A is transmitting the synchronization burst on the physical channel different from the previous time in response to the link CH establishment request message. Handset C1
No synchronization is established in the physical channel between the master unit A and the slave unit C1 by the synchronization burst.

Next, the SABM is transmitted from the master unit A (d1
2) Then, the child device C2 that has received this SABM transmits this SABM to the child device B (d13). When SABM is received by the slaves B and C2, the S
The UA is returned to each corresponding to the ABM (d14).

After returning UA in the handset B,
When it is determined that the link CH has been established, an incoming call response message is transmitted at a predetermined timing (d15), and the child device C2
Then, the incoming call response message from the handset B is temporarily stored in the memory 4, read at a predetermined timing and transmitted to the base A (d16). Child device C2 in parent device A
When an incoming call response message relayed by the slave unit B is received by the slave unit B, a predetermined message for setting various functions used for a call between the master unit A and the slave unit B is transmitted and received in the same manner as above. This is done by relaying machine C2.

When the various functions used for the call between the base unit A and the base unit B are set, the base unit A next makes a DISC.
C2 which originated (d17) and received this DISC
Transmits this DISC to handset B (d18).
When the cordless handsets B and C2 receive the DISC, the UAs are returned to the respective DISCs (d19).

When the base unit A receives the UA, it transmits a response message at a predetermined timing (d20), and the handset unit C2 stores the response message from the base unit A in the memory 4.
By temporarily storing the data in the mobile phone, reading the data at a predetermined timing, and transmitting the data to the mobile device B (d21), communication between the mobile device A and the mobile device C2 and between the mobile device B and the mobile device C2 is performed, and accordingly, the mobile device is performed. With C2 as a relay station, communication is established between the master unit A and the slave unit B, and a call is made possible.

Next, the operation control when determining whether or not to perform the relay in the slave unit that can be used as the relay station will be described based on the flowchart of FIG. It is assumed that the slave unit used as a relay station is provided with a relay ON / OFF button for switching whether to perform the relay operation and a setting button for setting a system limitation on the relay operation in the operation input unit 12. .

This flow chart is started when the main power source of the slave unit is turned on, and the process proceeds to step F1. In step F1, the receiving system 2a and the receiving system 2b of the wireless unit 2 are controlled and held in the standby state, and the process proceeds to step F2. In step F2, it is determined whether or not there is an incoming call message sent from another station. If it is determined that there is no incoming call message, the process proceeds to step F1 and the above operation is repeated, and it is determined that there is an incoming call message. If
The process moves to step F3.

In step F3, the originating identification code and the destination identification code are read from the incoming call message in step F2, and the process proceeds to step F4. In step F4, the source and the destination based on the originating identification code and the destination identification code read in step F3. Whether or not the original is the own system is judged. If it is judged as the own system, the process proceeds to step F5, and if it is judged not to be the own system, the process proceeds to step F6.

In step F5, it is determined whether or not the relay on / off button of the operation input unit 12 is set to the mode for performing the relay operation. If it is determined that the mode is for the relay operation, the process proceeds to step F7. If it is determined that the relay operation is to be performed here, the flow chart is ended, and if it is determined that the mode is not to perform the relay operation, the process proceeds to step F8 and it is determined that the relay operation is not performed here. The flowchart ends.

On the other hand, when it is determined in step F4 that the system is not the own system and the process proceeds to step F6, it is determined in step F6 whether or not the relay on / off button of the operation input unit 12 is set to the relay operation mode. If it is determined that the mode is the relay operation mode, the process proceeds to step F9. If it is determined that the mode is not the relay operation mode, the process proceeds to step F8 and it is determined that the relay operation is not performed. Then, this flowchart is finished.

Further, in step F9, it is judged by the setting button of the operation input section 12 whether or not it is the mode in which only the relay of the own system is carried out. If it is judged in the mode in which only the relay of the own system is carried out, step F8 If it is determined that the relay operation is not performed here, the flow chart is ended, and if it is determined that the mode is not only the relay of the own system, the process proceeds to step F7 and the relay operation is performed here. A determination is made and this flowchart is ended.

When it is determined in step F7 that the relay operation is performed, the relay operation control is performed after the end of this flowchart, and when it is determined that the relay operation is not performed in step F8, the wait is performed after the end of this flowchart. Move to receiving state.

Therefore, the relay ON / OFF button and the setting button of the operation input unit 12 can be used to judge whether or not the relay is to be performed, and it is possible to deal with the case where the relay station is not desired to be used. .

Next, the operation control for determining whether or not to perform the relay in the slave unit that can be used as the relay station based on the remaining battery level will be described with reference to the flowchart of FIG.

This flow chart is started when the main power source of the child device is turned on, and the process proceeds to step F21. In step F21, the receiving system 2a and the receiving system 2b of the wireless unit 2 are controlled and held in the standby state, and then in step F2.
Move to 2. In step F22, it is determined whether or not there is an incoming call message sent from another station. If it is determined that there is no incoming call message, the process proceeds to step F21 and the above operation is repeated, and it is determined that there is an incoming call message. If so, the process proceeds to step F23.

In step F23, the charge detection unit 11 determines whether or not the secondary battery 8 is being charged. When it is determined that the secondary battery 8 is being charged, it is determined that the relay operation is performed here in step F24. If the flow chart is ended and it is determined that charging is not in progress, the process proceeds to step F25.

In step F25, the remaining battery level of the secondary battery 8 is measured by the remaining battery level detector 10, and the step F2 is executed.
In step F26, it is determined whether or not the remaining battery level measured in step F25 is equal to or greater than a predetermined value and is sufficient.
If it is determined that there is enough, it proceeds to step F24, it is determined that the relay operation is performed here, and this flowchart is ended, and if it is determined that it is not sufficient, step F2
The process proceeds to step 6, and it is determined that the relay operation is not performed here, and this flowchart ends.

When it is determined in step F24 that the relay operation is performed, the relay operation control is performed after the end of this flowchart, and when it is determined that the relay operation is not performed in step F26, the wait is performed after the end of this flowchart. Move to receiving state.

Therefore, it is possible to judge whether or not to perform the relay depending on the state of charge of the secondary battery 8 and the remaining battery level.
When the remaining battery level is low, it is not used as a relay station, so that it can be operated as a relay station only when it does not affect the communication of the user of the slave unit used as a relay station.

In the present embodiment, the case where the relay station is the slave unit in the case of the extension call between the master unit and the slave unit as the wireless connection using the relay station has been described. However, the present invention is not limited to this. However, the relay station may be a master unit or a slave unit in a direct call between handset units, and in this direct call between handset units, a dedicated control carrier is not provided and the calling side is a carrier for communication. Since there is a method in which an empty slot is detected and a call is made and the called side scans all channels, when the calling side transmits a ringing signal, there are two or more empty slots in advance on a single frequency. , Or selecting two or more vacant slots on a single frequency when making a proxy call request, the frequency received at the relay station that received the proxy call request and at different transmission timings. Empty slot It may be to send a call signal with bets. Also, it is not limited to extension calls,
For example, the slave unit may be called in response to an incoming signal coming from the telephone line in the master unit.

[0082]

As described above, according to the inventions of claims 1 to 3, when there is no response from the called side to the called signal transmitted from the called side, the called side is called. Side determines that the called side is not within the communication range of the calling side and requests the called side to call the called side to another station in the communication range,
When another station within the communication area of the calling side receives this called side calling request, it sends a called signal to call the called side and relays between the calling side and the called side. Since it is possible to establish a wireless connection between the called party and the called party, it is possible to establish a wireless connection with the called party that is not within the communication area of the calling party, and to make a call.

According to the fourth aspect of the present invention, after the incoming call signal for calling the called side is transmitted, when the temporary response signal is sent from the called side in response to the incoming call signal, the temporary response signal is transmitted. The signal strength at the time of reception is detected and transmitted to the calling side as a detection signal, and when this signal is received at the calling side, the signal strength is detected and the signal strength and the signal strength included in the detection signal are detected. By selecting another station to be used for relaying based on this, it is possible to select the appropriate one as the relay station when there are multiple relay stations in the communication area of both the calling side and the called side, so that a good call It can be performed.

According to the fifth aspect of the present invention, when another station relaying between the calling side and the called side cannot perform the relay, a relay stop signal is transmitted to the calling side and the called side. However, when the calling side receives this relay stop signal, it sends an incoming call signal to the called side, and when there is no response from the called side to the called side, the called side is within the communication area of the calling side. Even if the other station performing the relay cannot perform the relay by requesting the called side to call the called side to the other station that is in the communication range,
Since it is possible to newly set another station as a relay station to establish a wireless connection while maintaining a wireless connection between the calling side and the called side, it is possible to prevent unintended disconnection of the call.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a slave unit of a digital cordless telephone which is an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an arrangement state of a master unit and a slave unit of the digital cordless telephone.

FIG. 3 is a control sequence diagram showing a relay operation in the digital cordless telephone.

FIG. 4 is a control sequence diagram showing a relay operation in the digital cordless telephone.

FIG. 5 is an explanatory diagram showing an arrangement state of a master unit and a slave unit of the digital cordless telephone.

FIG. 6 is a control sequence diagram showing a relay operation in the digital cordless telephone.

FIG. 7 is a control sequence diagram showing a relay operation in the digital cordless telephone.

FIG. 8 is a flowchart showing operation control of relay determination in the digital cordless telephone.

FIG. 9 is a flowchart showing operation control of relay determination in the digital cordless telephone.

[Brief description of reference numerals]

 1 Antenna 2 Radio Section 3 Signal Processing Section 4 Memory 5 Voice Codec Section 6 Speaker 7 Microphone 8 Secondary Battery 9 Power Supply Section 10 Battery Remaining Detection Section 11 Charge Detection Section 12 Operation Input Section 13 Control Section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04M 1/72

Claims (5)

[Claims] 1. A call is made up of a base unit and a plurality of handsets, with transmission and reception being different in time, and a direct call is made between the base unit and the handset and between the handset. In a digital cordless telephone capable of performing, when there is no response from the called side after transmitting the called signal for calling the called side, calling means for making a calling side call request to another station in the communication range, A digital cordless telephone, comprising: relay means for transmitting an incoming call signal for calling the called party and relaying between the calling party and the called party when the called party call request is received. 2. The calling means includes incoming call transmitting means for transmitting an incoming call signal for calling the called side, and determining means for determining whether the called side has responded to the incoming call signal transmitted by the incoming call transmitting means. 2. The digital cordless telephone according to claim 1, further comprising: a called-side call requesting means for sending a called-side call request to another station in the communication area based on the judgment result by the judging means. .. 3. The relay means includes an incoming call receiving means for receiving an incoming call signal to the called side, and calling side information and called side information from the incoming call signal received by the incoming call receiving means. Information reading means for reading, notifying means for notifying the calling side that the calling side is in the communication range based on the calling side information read by the information reading means, and a called side received after the notification by the notifying means 2. The digital cordless telephone according to claim 1, further comprising: proxy call-in means for transmitting a call-in signal for calling the called party based on the called-side information from the information reading means in response to the call request. 4. The relay means includes a provisional radio wave intensity detection means for detecting the radio wave intensity of a provisional response signal transmitted from the called side in response to the transmission of the call arrival signal, and a detection signal by the radio wave intensity detection means. To the calling side, the incoming call means includes a radio wave intensity detection means for detecting the radio wave intensity of the detection signal in response to the reception of the detection signal, and the radio wave intensity detection means. 2. The digital cordless telephone according to claim 1, further comprising: another station selecting means for selecting another station to be used for relaying based on the detected radio field intensity and the radio field intensity based on the detection signal. 5. The relaying means comprises stop signal transmitting means for transmitting a relay stop signal to the calling side and the called side when relay between the calling side and the called side becomes impossible, and the calling means. Responds to the relay stop signal by sending an incoming call signal that calls the called party, and when there is no response from the called party after sending the incoming call signal, the called party sends the call to the other station in the communication area. 2. The digital cordless telephone according to claim 1, wherein a call request is made.