JPH05244082A - Radio connecting method for cordless telephone - Google Patents

Abstract

PURPOSE:To prevent a control channel from being disturbed by generating a wave on a vacant channel, and designating another vacant channel when the number of channels from which no intermodulation distortion is detected is smaller than a prescribed number. CONSTITUTION:When a quasi-radio connection state is set and the wave is issued from a slave set (b), such wave is used as a test wave, and detection on the control ch1 of a control channel is performed by a squelch circuit in the radio transmission/reception circuit 3 in a master set (a) first, and a radio connection procedure is completed when no input is detected. When the input is detected on the control ch1, the detection is performed again on a control ch2. When the input is detected on both the control ch1 and ch2, a procedure of channel switching is performed again by designating another vacant channel by a speech channel switched from the master set (a) to the slave set (b). In such a way, such procedure is repeated until it is conformed that no disturbance wave due to the intermodulation distortion is generated on either at least the control ch1 or ch2 of the control channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless connection method for a cordless telephone.

[0002]

2. Description of the Related Art Intermodulation distortion occurs when two or more cordless telephones are wirelessly connected within a certain fixed range. The intermodulation distortion is generated by two or more radio waves, and its frequency is determined by the frequency of the communication channel used by the cordless telephone in the wireless connection state.

Therefore, when two or more cordless telephones are wirelessly connected, intermodulation distortion may disturb the control channel used for wirelessly connecting the cordless telephones. If jammed, the control channel becomes unavailable and other cordless telephones become unavailable.

Conventionally, as a method of preventing control channel interference due to intermodulation distortion, all communication channels in use are detected from the master unit to the slave unit or before calling from the slave unit, and the control channel is not disturbed by calculation. There was one that specified a free call channel, but this took too long.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless connection method for a cordless telephone, which does not cause control channel interference due to intermodulation distortion, in order to solve the above-mentioned problems of the prior art.

[0006]

In order to solve the above-mentioned problems, the present invention firstly describes a control channel in which a master unit a to a slave unit b.
Alternatively, in the wireless connection method of the cordless telephone in which the base unit a is called from the base unit a, the available call channel is designated and the channel is switched, and the base unit a and the base unit b are wirelessly connected. The radio wave is transmitted on the call channel, and at this time, the intermodulation distortion is detected on one or more control channels, and when the intermodulation distortion is not detected on at least a predetermined number of control channels, wireless connection is performed on the call channel. A wireless connection method for a cordless telephone, characterized in that, when the number of control channels for which no intermodulation distortion is detected is less than the predetermined number, another vacant communication channel is designated.

Therefore, for example, according to the present invention, first, the master channel a to the slave station b or the slave station b to the master station a on the control channel.
In the wireless connection method of the cordless telephone, in which a free call channel that can be used is designated and the channel is switched to wirelessly connect the base unit a and the base unit b, in the base unit a or the base unit a after the channel switching. Transmit the radio wave on the switched communication channel, and at this time, the master device a or slave device b on the receiving side detects intermodulation distortion on one or more control channels, and intermodulation distortion on at least a predetermined number of control channels. When the number of control channels for which intermodulation distortion is not detected is less than the above-mentioned predetermined number, a free communication channel is specified for that communication channel again. The channel is switched and the radio wave is transmitted and the intermodulation distortion is detected.

Further, for example, in the present invention, first, the master unit a is called by the master unit a on the control channel, or the master unit a is called by the slave unit b, and a vacant communication channel that can be used is designated and channel switching is performed. In a wireless connection method for a cordless telephone in which a cordless telephone is connected to a cordless handset b, when designating the call channel, the base unit a or the cordless handset b transmits a radio wave on an available call channel, and at this time, the base unit a or the slave unit b detects the intermodulation distortion in one or more control channels, and when the intermodulation distortion is not detected in at least a predetermined number of control channels, the usable communication channel is designated and the intermodulation distortion is designated. When the number of control channels that are not detected is less than the above-mentioned predetermined number, radio waves are transmitted again on the other available empty communication channels and the And performs the detection of the modulation distortion.

In the above-mentioned invention, it is assumed that the master unit a or the slave unit b having a built-in radio transmitter / receiver is used to transmit the radio wave in the empty communication channel and detect the intermodulation distortion in the control channel. The present invention is not limited to this, and for example, a wireless transmitter / receiver may be incorporated in a charger used for charging the slave unit b and used instead of the master unit a or the slave unit b.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a cordless telephone including a master unit a and a slave unit b connected to a line 1 according to the present embodiment. The master unit a is a 2-4 line conversion circuit 2, a wireless transmission / reception circuit 3,
A signal detection circuit 4 for detecting a signal transmitted from the line 1, a control circuit 5 for controlling telephone communication and wireless connection, an ID-for storing a common identification code of the master a and the slave b, etc. The slave device b includes a ROM 6 and the like, and the slave device b is a wireless transmission / reception circuit 7, a control circuit 8, a dial circuit 9, a master device a and a slave device b.
It is composed of an ID-ROM 10 for storing a common identification code and the like.

The control channel used for wireless connection between the master unit a and the slave unit b is defined by the Radio Law.
Both frequencies are used. In this embodiment, these two frequencies are used as control ch1 and control ch2.

Further, in this embodiment, the squelch circuit included in the radio transmitter / receiver circuit 3 of the master unit a is used as a means for detecting the intermodulation distortion in the control channel, and when the radio wave is transmitted in the empty communication channel, the control channel is used. The intermodulation distortion is detected by detecting an interfering radio wave based on the intermodulation distortion having the same frequency as the above.

With this configuration, wireless connection is performed based on the procedure shown in FIG. FIG. 2 (a) shows a case where there is no interference due to intermodulation distortion. The base unit a, which has detected an incoming call from the line 1, uses the control ch1 of the control channel to issue a call command (incoming call request signal, identification code and idle call). (Channel designation) is transmitted to call the slave device b. The child device b, which has received this calling command, transmits a calling response on the control ch1 to notify the parent device a of the reception of the calling command.
At this time, the slave unit b switches the channel to the designated communication channel. Similarly, the base unit a that receives the call response transmission
Switches to the specified call channel.

In addition, the detection of an empty call channel is performed by alternately performing the call channel detection and the call detection from the slave unit while the master unit a is waiting for an incoming call and a call, and the call channel for which an empty is detected is controlled by the control circuit each time. 5 is stored in the memory. When the idle call channel is designated at the time of wireless connection, the idle call channel information most recently stored in the memory is used.

When transmitting the call command, the master unit a
Is a control channel by the carrier determination circuit of the wireless transmission / reception circuit 3.
After confirming the vacancy of No. 1, transmission is performed on this control channel, and when the control ch1 is blocked, the vacancy of the control ch2 is confirmed and used.

As described above, when the master unit a and the slave unit b designate the vacant call channel to switch the channels, the slave unit b transmits a command to report that the channel switch is completed on this call channel. I do. Upon receiving this, the base unit a makes a call channel response. Further, the slave unit b which has received this enters the quasi-wireless connection state and transmits a radio wave on this call channel. The quasi-wireless connection state is a state for confirming that no interfering radio wave that interferes with the control channel is generated due to the intermodulation distortion.

Intermodulation distortion occurs when another cordless telephone approaching when the quasi-radio connection state is in a call state. Therefore, interfering radio waves due to intermodulation distortion are generated on both sides of both call channels at an interval equal to the frequency interval between the call channel used by the master unit a and the slave unit b and the call channel used by another cordless telephone. It will be. If the positions are on both the control ch1 and the control ch2, the control channel cannot be used at all, so that the third and subsequent cordless telephones installed close to each other cannot be used.

Therefore, in this embodiment, when the radio wave is transmitted from the slave unit b in the quasi-wireless connection state, this radio wave is used as a test radio wave, and the squelch circuit in the radio transmission / reception circuit 3 of the master unit a uses it. First, detection is performed by the control channel 1 of the control channel, and if there is no feeling of entry (if no interfering radio waves are detected), the above wireless connection procedure is completed. If there is a sense of acceptance in control ch1, detection is performed again in control ch2. If there is no feeling of feeling on the control ch2, other cordless telephones can use at least the control ch2, so that the wireless connection is completed on this call channel.

If both the control channel control channel 1 and the control channel channel 2 have a feeling of presence, as shown in FIG. 2 (b), the communication channel switched from the master device a to the slave device b is replaced with another empty communication channel. The channel switching procedure is designated and performed again, and each procedure up to the transmission of the radio wave and the detection of the interfering radio wave due to the intermodulation distortion is performed again. Thus, in order to specify the channel again, the master unit a and the slave unit b
Since both use the communication channel that has already been switched by the first channel designation, the control channels (control channel 1 and control channel) that cannot be used due to intermodulation distortion are used.
It is not necessary to use 2).

In this way, the control channel of the control channel
The above procedure is repeated until it is confirmed that the interfering radio wave due to the intermodulation distortion does not occur in at least one of 1 and control ch2.

As described above, when the wireless connection is performed, the radio wave is emitted in advance in the idle call channel, and the presence or absence of the interference due to the intermodulation distortion in the control channel is detected by the radio wave. It can be carried out.

In the above embodiment, the quasi-radio connection state is provided and the radio wave transmitted at that time is used to detect the intermodulation distortion. However, the present invention is not limited to this. If a further receiver is installed in the device a and the intermodulation distortion is always detected on the control channel, the mutual switching is transmitted by the command transmitted from the handset b at the time of the above-mentioned channel switching, and the mutual switching command is issued. It is possible to detect modulation distortion.

Further, in the above-described embodiment, another idle communication channel is designated only when both the control channels 1 and 2 of the control channel are disturbed by the intermodulation distortion, that is, when all of the plurality of control channels are disturbed. However, the present invention is not limited to this, and the intermodulation distortion is detected by one or a plurality of control channels, and at least a predetermined number (≧
When intermodulation distortion is not detected in the control channel of 1), wireless connection is established in the communication channel, and when the number of control channels in which intermodulation distortion is not detected is less than the predetermined number (≧ 1), etc. It suffices as long as it designates an available call channel and switches the channel again.

Further, in the above-mentioned embodiment, an example in which the inter-modulation distortion is detected after the call channel is designated and the channel is switched has been described, but the present invention is not limited to this. When specifying a channel, radio waves are transmitted on the unused communication channel to be specified, at this time intermodulation distortion is detected on one or more control channels, and at least a predetermined number (≧ 1) of control channels When no modulation distortion is detected, the available communication channel is designated, the channel is switched, and wireless connection is established, and the number of control channels in which no intermodulation distortion is detected meets the above-mentioned predetermined number (≧ 1). If not, the radio wave may be transmitted again through another available communication channel to detect the intermodulation distortion.

Further, in the above embodiment, an example is shown in which there is an incoming call from the line 1 to the base unit a and the base unit a calls the base unit a, but the same configuration is also applied when the base unit a calls the base unit a. Of course you can. Furthermore, in the above-described embodiment, an example has been shown in which the slave unit b emits radio waves and the master unit a detects intermodulation distortion, but the present invention is not limited to this, and these functions are It may be provided in any of the slave units, for example, the master unit emits radio waves and the slave unit detects intermodulation distortion, the master unit itself emits radio waves and detects intermodulation distortion, or the slave unit. Various modes are conceivable, such as providing a wireless transmitter / receiver to a charger for charging the above, and similarly making it possible to detect intermodulation distortion.

Therefore, since the present invention can be realized by using the squelch circuit of the wireless transceiver regardless of the structure of the cordless telephone, it can be easily realized in any cordless telephone.

[0027]

Since the present invention is constructed as described above, even if a large number of cordless telephones are arranged close to each other, the interference of the control channel due to the intermodulation distortion can be detected and prevented in an extremely short time. is there.

[Brief description of drawings]

FIG. 1 is a block diagram of a cordless telephone showing an embodiment of the present invention.

2A and 2B are sequence diagrams showing a wireless connection procedure of a cordless telephone showing an embodiment of the present invention.

[Explanation of symbols]

 a parent machine b child machine

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[Procedure amendment]

[Submission date] January 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Further, in this embodiment, the carrier determination circuit included in the radio transmitter / receiver circuit 3 of the master unit a is used as a means for detecting the intermodulation distortion in the control channel, and control is performed when a radio wave is transmitted in an empty communication channel. The intermodulation distortion is detected by detecting an interfering radio wave based on the intermodulation distortion having the same frequency as the channel.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Therefore, in this embodiment, when the radio wave is transmitted from the slave unit b in the quasi-radio connection state, this radio wave is used as a test radio wave, and the carrier determination circuit in the radio transmission / reception circuit 3 of the master unit a is used. First, control channel control channel 1
The detection is carried out at, and if there is no feeling of entry (if the interfering radio waves are not detected), the above wireless connection procedure is completed. Conversely, control c
If there is a feeling of entry at h1, detection is performed again at control ch2. At this time, if there is no feeling of feeling in the control ch2, other cordless telephones can use at least the control ch2, so that the wireless connection is completed in this call channel.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

Therefore, since the present invention can be realized by using the carrier determination circuit of the wireless transceiver regardless of the structure of the cordless telephone, it can be easily realized in any cordless phone.

Claims (1)

[Claims] 1. First, a master unit calls a slave unit or a slave unit from the slave unit by a control channel, and a channel switching is performed by designating an available communication channel to establish a wireless connection between the master unit and the slave unit. In the cordless telephone wireless connection method, radio waves are transmitted on the vacant communication channel, at this time, intermodulation distortion is detected on one or more control channels, and intermodulation distortion is not detected on at least a predetermined number of control channels. When the number of control channels for which intermodulation distortion has not been detected is less than the above-mentioned predetermined number, other vacant call channels are designated. How to connect.