JPH1032877A - Wireless communication system - Google Patents

Abstract

(57) [Problem] To provide a wireless communication system in which a plurality of slave units can be simultaneously connected to one external communication line. SOLUTION: Communication is performed between a parent device and a child device and between a child device and a child device by a time division method and a frequency hopping method. Make regular and conference calls. In a conference call, the base unit 10
In the transmission slot TB1, the audio data from the line is compressed to １ ／ and transmitted to the first slave unit 32 and the second slave unit 132. The first slave unit 32 compresses the audio data from the microphone to 1/4 in the transmission slot TH1, and transmits the compressed data to the master unit and the second slave unit. Similarly, the second slave unit 132 sets the transmission slot TK
In 2, the audio data from the microphone is compressed to 1/4 and transmitted to the master unit and the first slave unit. Each of the parent and child units expands the audio data received in the two reception slots (RB1, RB2, etc.) by four times and combines them into one audio data before outputting to the speaker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system having a master unit and a plurality of slave units.

[0002]

2. Description of the Related Art Conventionally, as a wireless communication system including one master unit connectable to two or more external communication paths and two or more slave units capable of wireless communication with the master unit, for example, A cordless telephone system disclosed in Japanese Patent Application Laid-Open No. 7-193861 is known.

In such a cordless telephone system,
The master unit is an NCU connected to each of a plurality of public lines.
An S / N (two-wire to four-wire conversion circuit) connected to each NCU, a codec connected to each S / N, and an RF unit for transmitting and receiving in a time-division manner between the cordless handset and In the case of a call with a public line, a digital signal to be connected to a codec and a wireless communication unit to convert the speed of a digital signal input from one of them and to be time-division multiplexed or time-division-separated and output to the other. It has a processing circuit.

In this cordless telephone system, the wireless section between the master unit and the slave unit is a time-division multiplex digital system, so that wireless communication with a plurality of slave units is possible at the same time. The circuit time-division separates the received digital signal, codec, S / N and NCU
Via a public telephone line. The analog signal arriving at the NCU is converted into a digital signal by the codec, and the digital signal processing circuit time-division multiplexes the input digital signals and transmits the digital signals from the RF unit to each slave unit. In this manner, a single parent device can simultaneously make an external line call with a plurality of child devices.

[0005]

However, in the above-mentioned cordless telephone system, any one of the slave units is connected to any one of the public lines, and a plurality of slave units are not connected to one public line at the same time. Was.

The present invention has been made in view of the above problems, and has as its object to provide a wireless communication system in which a plurality of slave units can be simultaneously connected to one external communication line.

[0007]

Means for Solving the Problems and Effects of the Invention To solve the above problems, a wireless communication system according to claim 1 is
A master unit connected to an external communication line, and a plurality of slave units that perform two-way wireless communication with the master unit in a time-sharing manner and that perform two-way wireless communication with each other in a time-sharing manner. Outputting the information input from the external communication line to the plurality of slave units in a time division manner, and outputting the information input in a time division manner from each of the plurality of slave units to the external communication line, Each of the plurality of slave units has an input unit for inputting information from outside and an output unit for outputting information to the outside, and transmits the information input from the input unit to the master unit and slave units other than the master unit. The information is output from the master unit and slave units other than the master unit in a time-division manner, and the synthesized information is output to the output unit.

[0008] In such a wireless communication system, when the master unit outputs information input from an external communication line to a plurality of slave units in a time-division manner, each of the plurality of slave units inputs this information.
When one of the plurality of slaves outputs information input from an input unit (for example, a microphone) to the master and another slave, the master and another slave input this information. . Then, each of the plurality of slaves sequentially outputs the information to the master and another slave, and the master and the other slave sequentially input the output information.

In other words, the master unit inputs information in a time sharing manner from each of the plurality of slave units, and each of the plurality of slave units inputs information in a time sharing manner from the master unit and a slave unit other than itself. . Then, the master unit outputs information input in a time-division manner from each of the plurality of slave units to the external communication line. For example, when the external communication line is an analog line, the input information is
And outputs the synthesized information (that is, the information in which a plurality of slaves are simultaneously communicating) to the external communication line. Further, for example, when the external communication line is an ISDN line, each input information is output as it is to the ISDN line. On the other hand, the slave unit combines information input in a time-sharing manner from the master unit and the slave unit other than the own unit, and synthesizes the combined information (that is, information that the other side of the external communication line and the slave unit other than the own unit simultaneously communicate with) ) Is output to an output unit (for example, a speaker or the like).

As described above, according to the wireless communication system of the first aspect, an effect is obtained that a plurality of slave units can be simultaneously connected to one external communication line. According to a second aspect of the present invention, in the wireless communication system according to the first aspect, the information is audio information.

According to such a wireless communication system, a plurality of slave units can be connected to one external communication line at the same time to make a call, so that an effect that a conference can be held is obtained. A third aspect of the present invention is the wireless communication system according to the first or second aspect, wherein a bidirectional communication is performed between the master unit and one of the plurality of slave units in a time-division manner. A normal mode in which the one slave unit and the external communication line can communicate with each other by performing wireless communication, and bidirectional wireless communication is performed in a time-division manner between the master unit and the plurality of slave units. A mode setting unit that sets any one of conference modes in which the plurality of slave units can communicate with the external communication line by performing two-way communication between the plurality of slave units in a time-division manner. It is characterized by having.

[0012] Such a wireless communication system includes a mode setting unit for setting one of a normal mode and a conference mode. In such a wireless communication system, when the mode setting unit is set to the normal mode, communication between one external communication line and one slave unit, that is, one-to-one communication, becomes possible. Communication between the external communication line and many slave units, that is, one-to-many communication is enabled.

According to such a wireless communication system, when the normal mode is set, the one-to-one connection between the external communication line and one slave unit is established.
Communication is enabled and the effect of preventing the communication contents from being known to other slave units is obtained. If the conference mode is set, one-to-many communication between an external communication line and a plurality of slave units is enabled, and each slave unit can communicate with each other. The effect that communication with the other party of the external communication line can be achieved is obtained.

According to a fourth aspect of the present invention, in the wireless communication system according to the third aspect, the mode setting section is provided in the master unit or the slave unit, and a user can arbitrarily select one of the modes. It can be set. According to such a wireless communication system, there is an effect that the user can set the normal mode or the conference mode as desired.

According to a fifth aspect of the present invention, in the wireless communication system according to the third or fourth aspect, the information compression ratio in the two-way wireless communication in the conference mode is higher than that in the normal mode. It is characterized by a higher compression ratio of information in two-way wireless communication.

In such a wireless communication system, as described above, when the mode setting unit is set to the normal mode, one-to-one communication between one external communication line and one slave unit becomes possible, and the conference mode is set. Then, one-to-many communication between one external communication line and a large number of slaves becomes possible.

By the way, in the normal mode, two-way wireless communication is performed by a time division method between the master unit and the slave unit (single unit), and in the conference mode, between the master unit and the slave unit (plural) and between the slave unit and the slave unit. Two-way communication is performed by a time division method. That is, in the normal mode, for example, a frame, which is one unit of bidirectional wireless communication in the master unit, can be configured only with a transmission slot to the slave unit (single) and a reception slot from the slave unit (single). it can. On the other hand, in the conference mode, for example,
In the master unit, a frame, which is one unit of the bidirectional wireless communication, needs to be configured with a transmission slot to the slave unit (plurality) and a reception slot from the slave unit (plurality). The number of transmission slots and reception slots increases.

At this time, assuming that the length of each slot in the conference mode is the same as that in the normal mode, the transfer rate becomes slower in the conference mode due to the larger number of slots. For this reason, it is preferable that the length of each slot in the conference mode be shorter than that in the normal mode so that the transfer rates of both modes are equal. That is, as described in claim 5, it is preferable that the compression rate of the information in the conference mode be higher than that in the normal mode so that the same amount of information can be output in a short slot.

According to such a wireless communication system, there is an effect that the transfer rates in the normal mode and the conference mode can be made equal. The invention according to claim 6 is the wireless communication system according to any one of claims 1 to 5, wherein the external communication line is an analog line, and the master unit receives an analog signal input from the analog line. Converting the signals into digital signals and outputting the digital signals to the plurality of slave units; synthesizing digital signals input from each of the plurality of slave units in a time-division manner; converting the synthesized digital signals into analog signals; Output to

In such a wireless communication system, the master unit combines digital signals input from each of the plurality of slave units in a time-division manner, for example, in an information combining unit, and the combined digital signal is sent to, for example, a D / A conversion unit. To convert it to an analog signal and output it to an analog line. By the way, it is also conceivable to convert a digital signal input from each of the plurality of slave units in a time-division manner into an analog signal, and then combine these analog signals and output the combined analog signal to an analog line. However, in this case, the number of D / A conversion units is required by the number of slave units, and the cost increases accordingly. On the other hand, in claim 6, since the digital signal is synthesized and then the synthesized digital signal is converted into an analog signal, only one D / A conversion unit is required when outputting to an analog line, which increases the cost. No effect is obtained.

The invention according to claim 7 is the wireless communication system according to any one of claims 1 to 6, wherein the external communication line is an ISDN line, and the master unit is connected to the ISDN line. An input digital signal is transmitted to the plurality of slave units, and a digital signal input from each of the plurality of slave units in a time division manner is output to the ISDN line.

According to this wireless communication system, the master unit synthesizes digital signals input from each of the plurality of slave units, as compared with the case where the external communication line is an analog line (for example, see claim 6). Output to the channel of the ISDN line without any change. For this reason, the information synthesizing unit and the D / A converting unit are not required, and the effect that the apparatus is simplified and the cost is reduced can be obtained.

According to an eighth aspect of the present invention, in the wireless communication system according to any one of the first to seventh aspects, each of the plurality of slave units converts an analog signal input from the input unit into a digital signal. The digital signal is output to the parent device and the child device other than the self device, and the digital signal input from the parent device and the child device other than the self device in a time division manner is converted to an analog signal. The data is output to the output unit.

In such a wireless communication system, each of the plurality of slave units combines digital signals input from the master unit and the slave units other than the slave unit in a time-division manner, for example, by an information combining unit, and combines the combined digital signals with, for example, The signal is converted into an analog signal by a D / A converter and output to an analog line. Again,
As in the sixth aspect, the number of D / A converters for outputting to the output unit may be one, and the cost is not increased.

According to such a wireless communication system, the effect that the cost of the entire system can be suppressed can be obtained. The ninth aspect of the present invention is the wireless communication system according to any one of the first to eighth aspects, wherein the two-way wireless communication between the master unit and the slave unit and between the slave unit and the slave unit are performed in a time-division manner. In addition, it is characterized in that it is performed by a spread spectrum method.

Here, the spread spectrum method is a well-known method that greatly widens the occupied bandwidth of a signal, and instead makes it more resistant to noise and interference, such as direct spreading and frequency hopping. According to such a wireless communication system, since the two-way wireless communication between the master unit and the slave unit and between the slave unit and the slave unit is performed by the spread spectrum method, there is little interference with other communication systems and mutual interference may occur. And the effect of high reliability and confidentiality is obtained.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the embodiment of the present invention
It is needless to say that the present invention is not limited to the following embodiments, and can take various forms within the technical scope of the present invention.

[First Embodiment] FIG. 1 is a block diagram showing a schematic configuration of a radio communication system according to a first embodiment, and FIG. 2 is a block diagram showing a schematic configuration of a transceiver of a master unit. As shown in FIG. 1, the wireless communication system according to the present embodiment includes one telephone line 12 (external communication line), one base unit 10,
The main unit 10 connects each of the sub units 32 and 132 to the telephone line 12.

As shown in FIG. 1, base unit 10 includes a line terminator 14 connected to telephone line 12 and a codec (A / A /
D converter 16, a compression / expansion unit 18, an information synthesizer 26, a transceiver 22, and a controller 28. The line terminator 14 is a telephone line 1 which is an analog line.
2 and an analog signal transmitted to the telephone line 12.

The codec 16 converts an analog signal input from the line terminator 14 into a digital signal and outputs the digital signal to the compression / decompression device 18, and converts a digital signal input from the information synthesizer 26 into an analog signal. Line termination 1
4 is output. The compression / expansion unit 18 compresses the signal input from the codec 16 at a predetermined compression rate and outputs the compressed signal to the transceiver 22. The compression / expansion unit 18 expands the signal input from the transceiver 22 at a predetermined expansion rate to synthesize information. Output to the device 26.

The information synthesizer 26 temporarily stores the digital signal expanded by the compression / expansion unit 18 in a buffer (not shown), synthesizes the digital signals and synthesizes them as a synthesized digital signal.
6 or the digital signal expanded by the compression / expansion unit 18 is output to the codec 16 as it is. When the conference mode is set by the mode setting button 41 of the slave unit 32 described later, the former process is performed, and when the normal mode is set, the latter process is performed.

As shown in FIG. 2, the transceiver 22 includes a modulator 61, frequency converters 62 and 67, amplifiers 63 and 66,
A transmission / reception switch 64 and a PLL circuit 69 are provided.
In the modulator 61, the carrier is modulated by a digital signal input from the compression / expansion unit 18 by, for example, a frequency shift keying method, and outputs an intermediate frequency signal. This intermediate frequency signal is converted by the frequency converter 62
The signal is converted into a high-frequency signal of a predetermined frequency by the local oscillation frequency from the L circuit 69. At this time, the PLL circuit 69
Is controlled by the controller 28. That is, the controller 28 outputs a control signal to the PLL circuit 69 based on a hopping pattern (for example, stored in a ROM) in which random frequencies are arranged in a predetermined order, and the PLL circuit 69 outputs a local signal corresponding to the control signal. It outputs the transmission frequency. The high-frequency signal converted by the frequency converter 62 is amplified by the amplifier 63, passes through the transmission / reception switch 64, and is transmitted from the antenna 24.

The high-frequency signal received by the antenna 24 passes through a transmission / reception switch 64 and is amplified by an amplifier 66.
The high-frequency signal is converted to an intermediate frequency signal using the local oscillation frequency from, and demodulated by the demodulator 68, and the demodulated digital signal is output to the compression / expansion unit 18.

The controller 28 includes a well-known CPU, RO
M, RAM, clock, etc.
6. The signal is connected to the compression / expansion device 18, the information synthesizer 26, and the transceiver 22 so as to be able to input and output signals, and controls each device according to a program stored in the ROM.

The first slave unit 32 is a telephone, and as shown in FIG. 1, a transceiver 34 having an antenna 33, a compression / expansion unit 35, an information synthesizer 36, a speaker 38 (output unit) and Codec 37 provided with microphone 39 (input unit)
And a controller 40.

The transceiver 34 is the transceiver 22 of the base unit 10.
Since the configuration is the same as that described above, the description thereof is omitted. The compression / expansion unit 35 expands the signal input from the transmitter / receiver 34 at a predetermined expansion rate and outputs the expanded signal to the information synthesizer 36, and also compresses the signal input from the codec 37 at a predetermined compression rate and transmits / receives the signal to the transmitter / receiver 34. Output to

The information synthesizer 36 temporarily stores the digital signal expanded by the compression / expansion unit 35 in a buffer (not shown), synthesizes the digital signals, and synthesizes them as a synthesized digital signal.
7 or the digital signal expanded by the compression / expansion unit 35 is output to the codec 37 as it is. That is, when the conference mode is set by the mode setting button 41 described later, the former process is performed by the controller 40, and when the normal mode is set, the latter process is performed.

The codec 37 converts the synthesized digital signal from the information synthesizer 36 into an audio analog signal and outputs it from the speaker 38, and outputs the audio analog signal from the microphone 39 to the compression / expansion unit 35. . The controller 40 includes a well-known CPU, ROM, RAM, clock, and the like. The controller 40 is connected to the transmitter / receiver 34, the compression / expansion unit 35, the information synthesizer 36, and the codec 37 so as to be able to input and output signals, and is stored in the ROM. Each device is controlled according to the following. The controller 40 is provided with a mode setting button 41, and the user can set either a normal mode or a conference mode.

The second slave unit 132 has the same configuration as the first slave unit 32, and therefore the description thereof is omitted. In addition, the second slave unit 1
For each of the 32 constituent elements, 100 is added to the reference numeral of each of the constituent elements of the first handset 32 (see FIG. 1). Next, a communication procedure in the present wireless communication system will be described. In this wireless communication system, two-way wireless communication is performed between the parent device and the child device and between the child device and the child device by a time division method and a frequency hopping method. Master device 10 is connected to one telephone line 12. As a result, each child device 32,
132 is connected to the telephone line 12 via the base unit 10.

At the time of a normal call (that is, at the time of the normal mode), as shown in FIG. 4, master device 10 communicates with a frame consisting of a frequency hop period (shown by oblique lines), a transmission slot TB1, and a reception slot RB1 as one unit. Perform the action,
The first slave unit 32 performs a communication operation with a frame including a frequency hop period (indicated by oblique lines), a reception slot RH1, and a transmission slot TH1 as one unit. In addition, the second slave unit 132
Is the same as that of the first slave unit 32 during normal communication.

In each slot, in addition to the voice data signal, control signals (synchronization signal, conference request signal, conference permission signal, confirmation signal, conference call signal, response signal, etc.) are transmitted and received. Here, the conference request signal is a signal transmitted from one of the slave units to the master unit 10 when the slave unit is set to the conference mode. The meeting permission signal is the master unit 1
0 is a signal indicating that after receiving the conference request signal from the slave, the slave is permitted to shift to the conference mode. The confirmation signal is a signal for the slave unit that has received the conference permission signal from the master unit 10 to notify the master unit 10 that the slave unit has certainly received the signal. The conference call signal is the master unit 10
Is a signal for calling, after transmitting the conference permission signal, a child device other than the child device requesting the conference to join the conference. The parent device response signal is a signal for confirming that the child device that has received the conference call signal will participate in the conference.

In the following, a one-to-one call between the telephone line 12 and the first handset 32 (call in the normal mode, at this time the second handset 132 waits in a sleep state in which each unit is shifted to a power saving state) The telephone line 12 and the first
A description will be given based on the flowchart of FIG. 3 and the time charts of FIGS. 4 to 6 by taking as an example a case where a one-to-many call (call in a conference mode) between the second slave units 32 and 132 is performed.

It is assumed that the master unit 10 and each of the slave units 32 and 132 are synchronized, and processes in which the last two digits of the step numbers in each flowchart of FIG. 3 match are performed substantially simultaneously. Shall be. In addition, the master unit 10 and the first and second slave units 32 and 132 have the same frequency hopping pattern (see Table 1 below).

[0044]

[Table 1]

[About Normal Call]
A description will be given based on the flowchart of FIG. 3 and the time chart of FIG. First, the processing of master device 10 will be described. When the process is started, the controller 28 of the base unit 10
Performs a frequency hop operation (S101). That is, hopping is performed to the frequency of the next row (next hop number) in the hopping patterns shown in Table 1 above.

Next, with the frequency stabilized after this hop, the transmission / reception switch 64 is switched to the amplifier 63 side to be in the transmission state, and the telephone line 12 is switched to the line terminator 1.
4. 1/2 at the compression / decompression unit 18 after passing through the codec 16
The compressed audio data signal (because there are two data slots in one frame) is transmitted to the slave unit 32 in the transmission slot TB1 (see FIG. 4) together with the control signal (S10).
2).

At this time, the half-compressed audio data signal is modulated by the modulator 61, converted into a high-frequency signal by the local oscillation frequency from the PLL circuit 69 in the frequency converter 62, and transmitted from the antenna 24. You. Then, after the transmission of the transmission slot TB1 to be transmitted to the first slave unit 32 is completed, the transmission / reception switch 64 is switched to the amplifier 66 to be in the reception state, and the audio data signal and the control signal from the first slave unit 32 are transmitted. The signal is received in the reception slot RB1 (see FIG. 4) (S104).

The received signal is converted to an intermediate frequency signal by the frequency converter 67 of the transceiver 22 using the local oscillation frequency from the PLL circuit 69, demodulated by the demodulator 68, and doubled by the compression / expansion device 18. Expanded, information synthesizer 2
6, the signal is converted into an analog signal by the codec 16 and transmitted to the telephone line 12 via the line terminator 14.

Then, after the reception of the reception slot RB1 received from the first slave unit 32 is completed, it is determined whether or not the control signal from the first slave unit 32 includes the conference request signal (S106). . Here, if the conference request signal is not included (NO in S106, refer to the left frame in FIG. 4), the processing from S101 onward is repeated again (S1).
The processing from 01 to S106 is referred to as “normal call”).
On the other hand, if the conference request signal is included (YE in S106)
S, refer to the right frame in FIG. 4), execute a conference transfer routine (S107 to S115) described later, and a conference call routine (S117 to S122) described later, and return to S101 again.

Next, the processing of the first slave unit 32 will be described. When the processing is started, the controller 40 of the first child device 32 hops to the same frequency at the same timing as the parent device 10 (S201). Then, with the frequency stabilized after the hop, the transmission / reception switch (not shown) of the transceiver 34 is switched to the reception state, and the audio data signal and the control signal from the master unit 10 are received in the reception slot RH1 (see FIG. 4). (S202).

The received signal is despread by the transceiver 34.
The audio data signal is demodulated, and the audio data signal is double-expanded by the compression / expansion unit 35, passes through the information synthesizer 36, is converted into an analog signal by the codec 37, and is output from the speaker 38 as audio. Then, after the reception for the reception slot RH1 received from the base unit 10 is completed, the transceiver 3
Then, a transmission / reception switch (not shown) 4 is switched to a transmission state, and it is determined whether or not the mode set by the mode setting button 41 is the conference mode (S203).

Here, if the set mode is not the conference mode (NO in S203), the audio data signal compressed by the microphone 39 via the codec 37 and the compression / decompression unit 35 into a half is transmitted to the conference request signal. Is transmitted to the base unit 10 in the transmission slot TH1 (see the frame on the left side of FIG. 4) together with the control signal not including the control signal (S204), and the processing from S201 onward is repeated again.

On the other hand, if the set mode is the conference mode (YES in S203), the voice data signal is transmitted together with the control signal including the conference request signal to the transmission slot TH1.
(See the frame on the right side of FIG. 4) and transmit to master device 10 (S
204), and thereafter, a conference transfer routine described later (S207)
To S215) and a conference call routine to be described later (S217).
To S222), and returns to S201 again.

Next, the second slave unit 132 will be described.
The second slave unit 132 waits in a sleep state in which each unit is shifted to the power saving state while the master unit 10 and the first slave unit 32 are performing a normal call. However, the frequency hop operation is executed even during the sleep. In other words, hop to the same frequency at the same timing as that of master device 10.

[Conference Transfer] Next, the conference transfer routine will be described with reference to the flowchart of FIG. 3 and the time chart of FIG. First, the processing of master device 10 will be described. The controller 28 of the base unit 10 hops to the frequency in the next row of the frequency hopping pattern (S
107) 1st time slot (transmission slot TB
1. Referring to FIG. 5 (a), an audio data signal and a control signal (including a conference permission signal) are transmitted to the first slave unit 32 (S1).
08) second time slot (reception slot RB
1. Referring to FIG. 5A, an audio data signal and a control signal (including a confirmation signal) are received from the first slave unit 32 (S1).
09).

Subsequently, the compression ratio of the compression / expansion unit 18 is set to 1 /
4. Change the expansion rate to 4 times (S110). At this time,
As shown in FIG. 5B, one frame includes a frequency hop period (indicated by diagonal lines) and four slots.
Subsequently, hop to the frequency in the next column of the frequency hopping pattern (S111).

Then, the audio data signal and the control signal are transmitted to the slave unit 32 in the first time slot (transmission slot TB1, see FIG. 5B) (S112), and the second time slot (transmission slot TB2, (See FIG. 5B)
Transmits a control signal (including a conference call signal) to the slave unit 132 (S113), and transmits a voice data signal and a control signal from the slave unit 32 in the third time slot (reception slot RB1, see FIG. 5B). The control signal (including the response signal) is received from the slave unit 132 in the fourth time slot (receiving slot RB2, see FIG. 5B) (S115).

Thereafter, a conference call routine described later (S11)
7 to S122), and return to S101 again. The conference call routine will be described later. Next, the first slave unit 3
The process 2 will be described. The controller 40 of the first child device 32 hops to the same frequency at the same timing as the parent device 10 (S207). Then, in the first time slot (receiving slot RH1, see FIG. 5A), the master unit 1 transmits the audio data signal and the control signal (including the conference permission signal).
0 (S208), and transmits a voice data signal and a control signal (including a confirmation signal) to the base unit 10 in the second time slot (transmission slot TH1, see FIG. 5A) (S209).

Subsequently, the compression ratio of the compression / expansion unit 35 is set to 1 /
4. The expansion rate is changed to 4 times (S210). At this time,
As shown in FIG. 5B, one frame includes a frequency hop period (indicated by diagonal lines) and four slots.
Subsequently, hop to the same frequency is performed at the same timing as that of master device 10 (S211).

Then, the audio data signal and the control signal are received from the base unit 10 in the first time slot (reception slot RH1, see FIG. 5B) (S212), and in the second time slot (empty slot). Wait (S213,
The voice data signal and the control signal are transmitted to the base unit 10 in the third time slot (transmission slot TH1, see FIG. 5B) (see FIG. 5B), and the fourth time slot (empty). Wait in the slot (see FIG. 5B) (S215).

Thereafter, a conference call routine described later (S21)
7 to S222), and returns to S201 again. The conference call routine will be described later. Next, the second slave unit 1
The process of No. 32 will be described. In the sleep state (S301), the second slave unit 132 receives a control signal including a conference call signal from the master unit 10 in the reception slot RK2 (S301).
313), and then transmit a control signal including a confirmation signal to the parent device 10 in the transmission slot TK2 (S315). And
The compression ratio of the compression / expansion unit 135 is changed to 1/4 and the expansion ratio is changed to 4 times (S316).

Thereafter, a conference call routine described later (S31)
7 to S322), and return to S301 again. The conference call routine will be described later. [Conference Call] Next, the conference call routine will be described with reference to the flowchart of FIG. 3 and the time chart of FIG.

First, the processing of master device 10 will be described.
The controller 28 of the base unit 10 hops to the frequency in the next column of the frequency hopping pattern (S117), and transmits the audio data signal and the control signal in the first time slot (transmission slot TB1, see FIG. 6) to the first handset 32. And the second slave unit 132 (S118), and waits in the second time slot (empty slot, see FIG. 6) (S119).
The audio data signal and the control signal are received from the slave unit 32 in the third time slot (reception slot RB1, see FIG. 6) (S120), and the audio data signal is received in the fourth time slot (reception slot RB2, see FIG. 6). And the control signal from the slave unit 132 (S121).

At this time, in the transmission slot TB1, the audio data signal compressed by the compression / expansion unit 18 from the telephone line 12 via the line terminator 14 and the codec 16 is transmitted to the first slave unit together with the control signal. 32, second child device 132
Sent to The audio data signals received in the reception slots RB1 and RB2 in a time-division manner are each expanded four times by the compression / expansion unit 18 and synthesized into one audio data by the information synthesizer 26. Is converted into an analog signal, whereby a signal in which the first handset 32 and the second handset 132 are simultaneously talking is transmitted to the telephone line 12.

Thereafter, it is determined whether or not the communication has been completed (S122), and if the communication has not been completed (N in S122).
O), the processing of S117 and the subsequent steps are repeated again, and when the processing is completed (YES in S122), the flow returns to S101. Next, the processing of the first child device 32 will be described. The controller 40 of the first child device 32 causes the same frequency to be hopped at the same timing as that of the parent device 10 (S217), and transmits the audio data signal and the control signal in the first time slot (transmission slot RH1, see FIG. 6). 10 (S218), and waits in the second time slot (empty slot, see FIG. 6) (S219), and transmits the audio data signal and control signal in the third time slot (transmission slot TH1, see FIG. 6). The data is transmitted to the parent device 10 and the second child device 132 (S220), the fourth time slot (reception slot RH2, see FIG. 6).
Then, an audio data signal and a control signal are received from the second slave unit 32 (S221).

At this time, in the transmission slot TH 1, the compression / expansion unit 35 sends the signal from the microphone 39 via the codec 37 to the 1
The audio data signal compressed to / 4 is transmitted to the parent device 10 and the second child device 132 together with the control signal. Further, the audio data signals received in a time-division manner in the reception slots RH1 and RH2 are each expanded four times by the compression / expansion unit 35 and synthesized into one audio data by the information synthesizer 36. Is converted into an analog signal, and a signal in which the parent device 10 and the second child device 132 talk at the same time is output from the speaker 38.

Thereafter, it is determined whether or not the communication has been completed (S222), and if the communication has not been completed (N in S222).
O), repeat the processing of S217 and subsequent steps, and when the processing is completed (YES in S222), return to S201. Next, the processing of the second slave unit 132 will be described. First child unit 132
The controller 140 makes the hop to the same frequency at the same timing as the base unit 10 (S317), and receives the audio data signal and the control signal from the base unit 10 in the first time slot (receiving slot RK1, see FIG. 6) ( S318), 2
It waits in the third time slot (empty slot, see FIG. 6) (S319) and receives the audio data signal and control signal from the first slave unit 32 in the third time slot (reception slot RK1, see FIG. 6) (S319). (S320) In the fourth time slot (transmission slot TK2, see FIG. 6), the audio data signal and the control signal are transmitted to the parent device 10 and the first child device 32 (S321).

At this time, in the transmission slot TK2, the compression / decompression unit 135 is transmitted from the microphone 139 via the codec 137.
Is transmitted to the master unit 10 and the first slave unit 32 together with the control signal. Further, the audio data signals received in the reception slots RK1 and RK2 in a time-division manner are each expanded four times by the compression / expansion unit 135 and synthesized into one audio data by the information synthesis unit 136. Is converted into an analog signal, a signal that the base unit 10 and the first handset 32 are talking at the same time is output from the speaker 138.

Thereafter, it is determined whether or not the communication has been completed (S322), and if the communication has not been completed (N in S322).
O), the process of S317 and the subsequent steps are repeated again, and when the process is completed (YES in S322), the process returns to S301. According to the wireless communication system of the present embodiment, the following effects can be obtained.
That is, an effect is obtained in which two slave units (the first slave unit 32 and the second slave unit 132) can be simultaneously connected to one telephone line 12, and a conference can be held by three parties.

In the normal mode, one-to-one communication between the telephone line 12 and one slave unit is made possible, so that the effect that the communication contents cannot be known to other slave units is obtained. And one-to-many communication with the two slave units can be obtained. Further, which mode is set can be set by the user using the mode setting button 41 as desired.

Since the length of each slot in the conference mode is made shorter than that in the normal mode and the information compression rate in the conference mode is made higher than that in the normal mode, the transfer rate does not decrease even when the conference mode is set. The effect of being equivalent to the normal mode is obtained.

Since the two-way wireless communication between the master unit and the slave unit and between the slave unit and the slave unit is performed by the spread spectrum method, there is little interference with other communication systems, and there is no interference between the communication systems and reliability. The effect of high confidentiality is obtained. In the base unit 10, after a plurality of digital signals received in a time division manner by the transceiver 22 are combined by the information combiner 26, the combined digital signal is converted into an analog signal by the codec 16 and transmitted to the telephone line 12. Therefore, the cost does not increase. That is, it is conceivable that each of the plurality of digital signals is converted into an analog signal, and then these analog signals are synthesized and transmitted to the telephone line 12 as a synthesized analog signal (for example, see other embodiments described later). In this case, as many codecs as the number of slaves are required, the cost increases accordingly. However, in the above embodiment, the cost is not increased because only one codec 16 is required.

[Second Embodiment] The wireless communication system of the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted. However, in the parent machine 10, the compression / expansion device 18
The signal input from the codec 16 is constantly compressed to 1/2 and output to the transmitter / receiver 22, and the signal input from the transmitter / receiver 22 is expanded twice in the normal mode and quadrupled in the conference mode. Output to the information synthesizer 26.

In the first slave unit 32, the compression / expansion unit 35 compresses the signal input from the microphone 39 to 時 に は in the normal mode and ４ in the conference mode and outputs the signal to the transceiver 34. The signal input from the transmitter / receiver 34 expands the signal from the parent device 10 by two times and the signal from the second child device 132 by four times, and outputs it to the information synthesizer 36. The same applies to the second slave unit 132.

Next, a communication procedure of the wireless communication system according to the present embodiment will be described.

Hereinafter, as in the first embodiment, the telephone line 1
A one-to-one call between the second slave unit 32 and the first slave unit 32 (call in the normal mode, at this time the second slave unit 132 is in a sleep state in which each unit is shifted to a power saving state), and in the middle of that A description will be given of an example in which a one-to-many call (call in a conference mode) between the telephone line 12 and the first and second slave units 32 and 132 is performed.

[Normal Call] At the time of a normal call, the master unit 10 and the first slave unit 32 operate in the same manner as in the first embodiment, so that the time chart of FIG. 4 is obtained. [Regarding Conference Transition] The conference transition will be described based on the time chart of FIG.

That is, the base unit 10 that has received the conference request signal from the first handset 32, after the frequency hop (indicated by diagonal lines in FIG. 7A), takes the first time slot (the transmission slot TB).
1, see FIG. 7 (a)) to transmit the audio data signal and the control signal (including the conference permission signal) to the first slave unit 32, and the second time slot (reception slot RB1, FIG. 7 (a)).
), The audio data signal and the control signal (including the confirmation signal) are received from the first slave unit 32. On the other hand, the first child device 32
Is the first time slot (reception slot RH1, after the frequency hop (shown by oblique lines in FIG. 7A), FIG. 7A)
7), a voice data signal and a control signal (including a conference permission signal) are received from the master unit 10, and a voice data signal and a control signal (confirmation) are received in a second time slot (transmission slot TH1, see FIG. 7A). (Including a signal) to the base unit 10.

Thereafter, master device 10 changes the expansion ratio of compression / expansion device 18 to four times (the compression ratio remains １ ／).
Further, the first slave unit 32 sets the compression ratio of the compression / expansion unit 35 to １ ／.
And the expansion rate is set to 2 for the signal from the base unit 10.
As it is, the signal from the second slave unit 132 is changed to four times.

Therefore, as shown in FIG. 7B, the frames of the master unit 10 and the first slave unit 32 are composed of a frequency hop period (indicated by diagonal lines) and three slots. At this time, the transmission slot of the parent device 10 and the reception slot of the first child device 32 receiving the transmission slot are twice as long as the other slots.

Then, as shown in FIG.
0 uses the transmission slot TB1 and the reception slot RB1, the first slave unit 32 performs bidirectional communication using the reception slot RH1 and the transmission slot TH1, and the base unit 10 transmits information including a conference call signal in the transmission slot TB2. To the second slave unit 132, and the second slave unit 132 receives the reception slot RK.
Receive it at 2.

Then, in the next frame, base unit 10 uses transmission slot TB1 and reception slot RB1, first child unit 32 performs bidirectional communication using reception slot RH1 and transmission slot TH1, and the second Slave unit 132 transmits a control signal including a response signal in transmission slot TK2, and base unit 10 transmits the signal in second slot 13 in reception slot RB2.
2 to receive. After that, the second slave unit 132 changes the compression ratio of the compression / expansion unit 135 to ４, and maintains the expansion ratio of the first slave unit 32 for the signal from the master unit 10 at 2 times.
Is changed to four times.

[About Conference Call]
Description will be made based on the time chart of FIG. That is, the base unit 10 transmits the data to the first handset 32 and the second handset 132 in the transmission slot TB1, and the first handset 32 transmits this to the reception slot R1.
H1 and the second handset 132 receives this in the reception slot R
Receive at K1. In addition, the first slave unit 32 has a transmission slot T
At H1, the data is transmitted to the parent device 10 and the second child device 132,
Receives this in the reception slot RB1, and
Receives this in the reception slot RK2. Further, the second handset 132 transmits to the master unit 10 and the first handset 32 in the transmission slot TK2, the master unit 10 receives this in the reception slot RB2, and the first handset 32 receives this in the reception slot RH2. Receive.

At this time, in master unit 10, transmission slot T
In B1, the audio data signal compressed by the compression / expansion unit 18 from the telephone line 12 through the line terminator 14 and the codec 16 is transmitted together with the control signal to the first slave unit 32 and the second slave unit.
It is transmitted to slave unit 132. Also, the reception slots RB1,
The audio data signal received by the RB2 in a time-division manner is expanded four times by the compression / expansion unit 18 and synthesized into one audio data by the information synthesizer 26, and then converted into an analog signal by the codec 16. By doing so, the first child device 32
A signal in which the telephone and the second slave unit 132 are simultaneously talking is transmitted to the telephone line 12.

In the first slave unit 32, the transmission slot T
At H1, the audio data signal compressed by the compression / expansion unit 35 from the microphone 39 via the codec 37 to 1/4 is transmitted to the master unit 10 and the second slave unit 132 together with the control signal.
The audio data signals received in a time-division manner in the reception slots RH1 and RH2 are doubled by the compression / decompression device 35, respectively.
After being expanded by a factor of four, synthesized into one audio data by the information synthesizer 36, and converted into an analog signal by the codec 37, the master unit 10 and the second slave unit 132 talk at the same time. Is output from the speaker 38.

The second slave unit 132 is the same as the first slave unit 32. According to the wireless communication system of the second embodiment,
In addition to the effects similar to (1) to (1) of the first embodiment, the compression rate of the signal from the master unit 10 remains at 1/2, so that the effect of reducing the sound quality deterioration due to compression can be obtained.

[Third Embodiment] As shown in FIG. 9, the wireless communication system of the third embodiment has an ISDN line 52 (external communication line), one master unit 50, and first and second child units. Machine 3
2 and 132, and the parent device 50 is
2 and the ISDN line 52.

As shown in FIG.
DSU 53 (Digital Service)
es Unit: a digital line connection device), a channel controller 54, a compression / expansion unit 18, a transceiver 22, and a controller 28.

The ISDN line 52 has two 64 kbps B channels (referred to as B1 and B2, respectively) and a 16 kbps B channel.
One s D channel can be used. The B channel is used for information transmission, and the D channel is used for communication control and information transmission by a packet switching system. These channels are TDD (Time Division Dupl)
ex: time division multiplexing). DSU5
Communication between the base station 3 and the base unit 50 is performed at a speed of 192 kbps for both transmission and reception.

The channel controller 54 is a device for extracting a digital signal sent from the DSU 53.
The configurations of the compression / expansion unit 18, the transceiver 22, and the controller 28 are the same as those in the first embodiment, and thus the description thereof is omitted. Regarding the operation of base unit 50, during a normal call, DSU5
The digital signal from 3 is taken out for each channel by the channel controller 54, compressed by the compression / expansion unit 18 to be halved, and transmitted from the transceiver 24 to the first handset 32 and the second handset 132 from the antenna 24. Is done. The signals received from the first handset 32 and the second handset 132 received by the antenna 24 are taken out by the transceiver 22, expanded twice by the compressor / decompressor 18, and DSU by the channel controller 54 for each channel.
53. On the other hand, during a conference call, the compression / expansion unit 18 changes the compression ratio from １ ／ to 、 and sets the expansion ratio to 2
The operation is changed from double to quadruple, and the same operation as in the normal call is performed.

Since the configurations and operations of the first and second slave units 32 and 132 are the same as those of the first embodiment, a description thereof will be omitted. A communication procedure of the wireless communication system according to the present embodiment will be described. Hereinafter, as in the first embodiment, a one-to-one call between the telephone line 12 and the first handset 32 (call in the normal mode, at which time the second handset 132 has shifted its components to the power saving state). And the telephone line 12 and the first and second slave units 32,
A case of making a one-to-many call (call in conference mode) 132 will be described as an example.

However, at the time of a normal call and at the time of transition to a conference, the master unit 50 and the first slave unit 32 operate in substantially the same manner as in the first embodiment, and therefore the time charts of FIGS. 4 and 5 are obtained. The conference call will be described with reference to the time chart of FIG. Here, a description will be given assuming that the other party also performs a call using a wireless communication system having the same device configuration. At this time, the master unit 50, the first slave unit 32, and the second slave unit 1
32 frames are composed of a frequency hop period (indicated by oblique lines) and three slots.

In FIG. 10, master unit 50 transmits a signal received from, for example, the B1 channel of ISDN line 52 to first slave unit 32 and second slave unit 132 in transmission slot TB1. On the other hand, the first child device 32 receives this in the reception slot RH1, and the second child device 132 receives this in the reception slot RK1.

Next, master unit 50 transmits the signal received from, for example, the B2 channel of ISDN line 52 to first slave unit 32 and second slave unit 132 in transmission slot TB2. On the other hand, the first child device 32 receives this in the reception slot RH2, and the second child device 132 receives this in the reception slot RK2.

Subsequently, the first slave unit 32 sets the transmission slot TH
In step 1, the input signal from the microphone 39 is transmitted to the parent device 50 and the second child device 132. On the other hand, master unit 50 receives slot RB
1 and the second slave unit 132 receives the slot RK.
3 receives this. Further, the second slave unit 132 transmits an input signal from the microphone 139 to the master unit 50 and the first slave unit 32 in the transmission slot TK2. On the other hand, base unit 50 receives this in reception slot RB2, and first child unit 32 receives this in reception slot RH3.

Here, parent device 50 receives reception slot RB1
Is transmitted to, for example, the B1 channel of the ISDN line 52, and the signal received in the reception slot RB2 is transmitted to the ISDN line 52.
The data is transmitted to, for example, the B2 channel of the DN line 52. Also,
The first slave unit 32 includes reception slots RH1, RH2, and RH3.
The information synthesizer 36 converts the signal received in time-division into one synthesized digital signal, converts the synthesized digital signal into an analog signal by the codec 37, and outputs the sound from the speaker 38. Similarly, the second handset 132 receives the reception slot RK
1, the signals received in a time division manner at RK2 and RK3 are combined into one combined digital signal by an information combiner 136, and the combined digital signal is converted into an analog signal by a codec 137;
The sound is output from the speaker 138.

According to the wireless communication system of the third embodiment,
The first handset 32 and the second handset 132 are simultaneously connected to one ISDN
The connection with the line 52 can be established, and an effect is obtained in that a conference can be held between the two slave units and the other two slave units. Further, the effects (1) to (3) of the first embodiment can be obtained.

[0098] Further, compared with the case where the external communication line is an analog line as in the first embodiment, master unit 50 converts the digital signal input from each of first slave unit 32 and second slave unit 132. The signals can be output to different channels B1 and B2 of the ISDN line 52 without combining. For this reason, the master unit 50 does not require an information synthesizer or a codec as compared with the master unit 10 of the first embodiment, and has an effect that the apparatus is simplified and the cost is reduced.

Of course, master unit 50 may output signals from slave units 32 and 132 to one channel, for example, B1. [Other Embodiments] With respect to the master unit 10 of the first embodiment,
The configuration may be as shown in FIG. 11 (the controller is omitted). That is, between the line terminator 14 and the compression / expansion unit 18, a path through which the signal output from the line termination unit 14 is input to the compression / expansion unit 18 via the A / D converter 94, The path through which the output signal is input to the line terminator 14 via the first buffer 95, the first D / A converter 97, and the information synthesizer 99, and the signal output from the compression / expansion unit 18 is transmitted to the second buffer 96, It may have a path for input to the line terminator 14 via the 2D / A converter 98 and the information synthesizer 99.

At this time, in master unit 10, audio data signals received in a time-sharing manner from first slave unit 32 and second slave unit 132 are individually converted into analog signals by D / A converters 97 and 98, respectively. Thereafter, the information is synthesized by the information synthesizer 99 and output to the line terminator 14 as a synthesized analog signal.

In this case, the number of D / A converters required is equal to the number of slave units, but the effects of the first embodiment can be obtained. In the same manner as above, the first slave unit 32 and the second slave unit 132 individually receive digital signals received in a time-sharing manner from the master unit 10 and slave units other than the own unit by two D / A converters. After conversion into an analog signal, the information synthesizer may output the analog signal from the speakers 38 and 138 as a synthesized analog signal.

The number of slave units is not limited to two, but can be set arbitrarily. In this case, the data compression ratio and expansion ratio may be changed according to the number of slave units.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a wireless communication system according to a first embodiment.

FIG. 2 is a block diagram illustrating a schematic configuration of a transmitter / receiver of a master unit.

FIG. 3 is a flowchart illustrating a communication procedure according to the first embodiment.

FIG. 4 is a time chart during a normal call in the first embodiment.

FIG. 5 is a time chart at the time of shifting to a conference according to the first embodiment.

FIG. 6 is a time chart during a conference call according to the first embodiment.

FIG. 7 is a time chart at the time of shifting to a conference in the second embodiment.

FIG. 8 is a time chart at the time of a conference call according to the second embodiment.

FIG. 9 is a block diagram illustrating a schematic configuration of a wireless communication system according to a third embodiment.

FIG. 10 is a time chart at the time of a conference call according to the third embodiment.

FIG. 11 is a block diagram illustrating a schematic configuration of a wireless communication system according to another embodiment.

[Explanation of symbols]

10: master unit, 12: telephone line, 14: line terminator, 16: codec, 18: compression / expansion device, 22: transceiver, 24: antenna, 26・
..Information synthesizers, 28 ... controllers, 32 ...
Slave unit, 33 ... antenna, 34 ... transceiver, 35
... compressor / expander, 36 ... information synthesizer, 37 ...
Codec, 38 ... speaker, 39 ... microphone,
40: controller, 41: mode setting button.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location 9744-5K H04L 11/18

Claims (9)

[Claims] 1. A master unit connected to an external communication line, performing bidirectional wireless communication with the master unit in a time-division manner,
A plurality of slave units for performing two-way wireless communication with each other in a time-division manner, wherein the master unit outputs information input from the external communication line to the plurality of slave units in a time-division manner, and And outputting information input from each of the mobile units in a time-division manner to the external communication line. Each of the plurality of slave units has an input unit for inputting information from the outside and an output unit for outputting information to the outside And outputs the information input from the input unit to the parent device and the child device other than the self device, synthesizes the information input in a time-sharing manner from the parent device and the child device other than the self device, and synthesizes the synthesized information. A wireless communication system for outputting to the output unit. 2. The wireless communication system according to claim 1, wherein said information is voice information. 3. The wireless communication system according to claim 1, wherein two-way wireless communication is performed between the master unit and one of the plurality of slave units in a time-division manner. Performing a normal mode in which the one slave unit and the external communication line can communicate with each other, and performing two-way wireless communication in a time-division manner between the master unit and the plurality of slave units, and A mode setting unit that sets any one of conference modes in which the plurality of slave units and the external communication line can communicate with each other by performing two-way communication in a time-division manner between the slave units. A wireless communication system, comprising: 4. The wireless communication system according to claim 3, wherein the mode setting unit is provided in the master unit or the slave unit, and a user can arbitrarily set one of the modes. A wireless communication system, characterized by: 5. The wireless communication system according to claim 3, wherein the information compression ratio in the two-way wireless communication in the conference mode is higher than the information compression rate in the two-way wireless communication in the normal mode. A radio communication system characterized by having a compression ratio higher than the compression ratio. 6. The wireless communication system according to claim 1, wherein the external communication line is an analog line, and the master unit converts an analog signal input from the analog line into a digital signal. And converting the combined digital signal into an analog signal and outputting the signal to the analog line. A wireless communication system, comprising: 7. The wireless communication system according to claim 1, wherein the external communication line is an ISDN line, and the master unit transmits a digital signal input from the ISDN line to the wireless communication system. A wireless communication system transmitting to a plurality of slaves and outputting a digital signal input from each of the plurality of slaves in a time division manner to the ISDN line. 8. The wireless communication system according to claim 1, wherein each of the plurality of slave units converts an analog signal input from the input unit into a digital signal, and converts the analog signal into a digital signal. Output to the master unit and the slave unit other than the self unit, synthesize digital signals input from the master unit and the slave unit other than the self unit in a time-sharing manner, convert the synthesized digital signal into an analog signal, and output to the output unit. A wireless communication system, comprising: 9. The wireless communication system according to claim 1, wherein the two-way wireless communication between the parent device and the child device and between the child device and the child device are performed in a time-division manner and in a spectrum. A wireless communication system, wherein the communication is performed by a spreading method.