JP2003047067A - Digital cordless telephone device and its call channel allocating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a collision of a call channel in a system in a digital cordless telephone device of a DSS(direct spread spectrum communication) system to realize a multi-band system by making a complicated control unwanted. SOLUTION: All usable call channels are divided by the number of sets of extension phones 12a to 12b, and the number is allocated to each extension phone, thereby carrying out multichannel access.

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 device connected by a plurality of wireless channels using a spread spectrum communication system and a method for allocating a speech channel thereof.

[0002]

2. Description of the Related Art Conventionally, a spread spectrum communication system has been widely used for mobile communication as a communication system having a wide occupied frequency band and excellent noise resistance and interference.

Various methods have been proposed as a spread spectrum method, and one of them is a direct spread spectrum (hereinafter referred to as DSS) method.

FIG. 15 shows the principle of this DSS transmission / reception system. On the transmitter side, transmission digital information D ₁ is transmitted.
Is performed by dividing the modulation into two stages, the primary modulator 1 is FSK (frequency modulation), PSK (phase modulation), etc., and the secondary modulator 2 in the latter stage corresponds to a spread modulator, and the primary modulator 1 The signal modulated by is M (Maximum Length Cod).
e) PN (Pseudorandom Noi) such as series
se) The wideband ± 1 signal waveform from the sequence generator 3 is 2
It is multiplied by the next modulator 2 and sent to the transmitting antenna 5 via a BPF (band pass filter) 4.

Since the secondary modulator 2 multiplies the FSK signal and the like by the PN sequence, the spectrum distribution thereof is in the form of convolution integration of the spectrum of the FSK primary modulation signal and the spectrum of the PN sequence, and the bandwidth after spread modulation. Is the sum of the modulation width of the primary modulator 1 and the PN sequence, and the bandwidth of the PN sequence is substantially the bandwidth of the spread signal.

On the receiver side, the spread spectrum signal received by the receiving antenna 6 is spread over a wide band by re-multiplying the same waveform as the PN sequence used on the transmitter side by the secondary demodulator 8 via the BPF 7. The spectrum component is 1
Returning to the spectrum band at the time of the next modulated wave, the demodulated output is taken out through the demodulator 10 such as a normal FSK.

FIG. 16 shows an example of a digital cordless telephone device using the DSS system as described above. In FIG. 16, the base unit 11 has a plurality of communication channels CH1 to CHn.
One fixed control channel C-CH1 is provided. Reference numeral 13 is a public line such as a central office line, and 17 is an AC power supply unit. The parent device 11 and the child devices 12a to 12d are provided with transmission / reception shared antennas 14 and 15, respectively.

[0008]

In the above digital cordless telephone device of the DSS communication system, basically, the telephone call is configured so that, for example, the telephone call can be made only 1: 1 between the base unit 11 and the handset units 12a to 12d. .

Now, assuming that there is a channel of 40 channels between the base unit 11 and the plurality of handset units 12a and 12b as shown in FIG. 17, consider the case where a call is made between the base unit 11 and the handset unit 12a. Then, one predetermined channel, for example, three channels are fixed as control channels. Calls are made between the master unit 11 and the slave unit 12a through three control channels. In this case, if the three channels are empty channels, the control channel is switched to the communication channel.

When the three channels are busy or the disturbance noise is large, the master unit 11 searches for an empty channel or a channel with little disturbance noise over the band of 1 to 40 channels of all the channels.

Accordingly, there is a call between the second handset 12b and the base unit 11 while the base unit 11 and the handset 12a have a call on the 10th channel, for example, on the 40th channel, and the desired call channel, for example, 40th channel. If it is busy, the base unit 11 is 1
In order to search for an empty channel or a channel having no disturbance noise over the entire band of 40 channels, noise will naturally increase when approaching the vicinity of 10 channels during a call, and the collision rate of the communication channel will also increase, and thus the base unit 11 And cordless handset 1
2a to 12d have a problem that they can be dealt with only at 1: 1.

The present invention has been made in order to solve the above problems, and the problem to be solved by the present invention is to enable multi-channel access that enables simultaneous use of a communication channel, and (EN) A digital cordless telephone device which avoids collision of call channels and a call channel assigning method thereof.

[0013]

SUMMARY OF THE INVENTION The present invention according to claim 1 is a digital cordless telephone device having a master unit and a plurality of slave units connected by a plurality of channels for transmitting and receiving in a spread spectrum system, and having a number of channels. To obtain a quotient value obtained by dividing the number of slave units by a plurality of slave units, and assigning to each different slave unit a different channel group corresponding to the quotient value.

The present invention according to claim 2 is characterized in that the number of channels corresponding to the quotient value among the number of channels is fixed as a control channel, and the others are communication channels. It is what

According to a third aspect of the present invention, there is provided a call channel assigning method for a digital cordless telephone device having a master unit and a plurality of slave units connected by a plurality of channels for transmitting and receiving, wherein the number of channels is a plurality of slave units. This is a method for allocating a call channel of a digital cordless telephone, characterized in that a quotient value divided by a number is obtained and assigned to different channel groups corresponding to the quotient value for each of a plurality of slave units.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A digital cordless telephone device and a call channel allocating method thereof according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows D detailed in FIG.
Base station 11 of SS cordless telephone system
It is a block diagram which shows the detailed structure of the cordless handsets 12a-12n. In FIG. 1 (A), a main line 11 has a public line interface 16 connected to a public line 13 such as a station line,
There is provided a voltage source 17 which is supplied with or has a built-in DC voltage such as a battery.

An analog signal from a public line interface 16 including a line switch and a hybrid circuit for controlling a direct current and a call signal from the public line 13 is supplied to a DSP (digital signal processor) 18.

In the DSP 18, an analog-interface 18a for converting an analog signal into digital data, a microcomputer interface (CPU-I / F) 18b connected to a main microcomputer (CPU) 19 by a bus, and an adaptive differential pulse encoding process. ADPCM (adaptive difference PCM) codec 18c for performing

The main CPU 19 is a CP in the public line interface 16, the RF chip IC 20 and the DSP 18.
Data and control signals are exchanged via the bus with the non-volatile memory (ROM) 19a in which the U-I / F 18b and the communication ID are stored.
Microcomputer interface in 0 (CPU-I / F) 20
connected to b.

The output data of the ADPCM codec 18c is supplied to the ADPCM, FIFO (first-in first-out) buffer 20a of the RF chip IC 20, and the buffer data is first-in / first-out.

The output data of the ADPCM, FIFO buffer 20a and CPU I / F 20b are TDD (Time).
Division Duplex: Time division bidirectional transmission method) The burst mode control / timing generator unit 20c supplies the timing signal to perform the primary modulation and demodulation and the second modulation.
Spread spectrum processing and despread processing are performed by the FSK modem and the spread processing and the despread processing unit 20d for performing FSK such as the next modulation and demodulation.

Further, the handset 12 is provided in the RF chip IC 20.
a to 12d and a receiver 20e that demodulates a received signal through a wireless line, a synthesizer 20f that generates an outgoing signal corresponding to a channel, that is, a call channel 24 and a control channel 25, and a slave unit 12a to 12d through a wireless circuit to a primary A transmitter 20g for transmitting the modulated and secondarily modulated high frequency signal is built in.

The output and input of the RF chip IC 20 are connected to the transmission / reception shared antenna 14 via an RF interface 21 including an antenna duplexer or the like.

The slave units 12a to 12d have the same structure, and each slave unit has a receiver 2 as shown in FIG. 1 (B).
2 and the microphone 23 perform adaptive differential pulse encoding processing A
The configuration is the same as that of the parent device except that it is connected to the RF chip IC 20 via the DPCM codec, and therefore corresponding parts will be denoted by the same reference numerals and redundant description will be omitted.

The communication protocol between the master unit 11 and the slave units 12a to 12d of the block described above is based on the RF chip IC2.
0 to the 2.4 GHz spread spectrum digital cordless telephone device (2.4 GHz Spread Spectr
um Digital Cordless Telop
1-chip IC for the phone transceiver)
An example of a DSS system in which (Intel ALPINE LXT821) is used and transmission / reception can be performed with up to four slave units will be described below.

The RF chip IC 20 used in this example is the base unit 1.
1 and the predetermined slaves 12a to 12d and the predetermined slaves 12a to 12d can talk with each other without the master 11.

The channel of this example is a 40-channel MC.
A (Multi-Channel Access) can be performed, and as shown in FIGS. 2 and 3, transmission / reception between the master unit 11 and the slave units 12a to 12d is performed by two channels of a control channel 25 and a call channel 24.

Of the 40 available channels, 4 channels of the control channels 25 in the 14-bit communication ID (16384 ways) stored in the ROM 19a are used as the control channels 25. As shown in FIG. 2, the relationship between the communication ID and the control channel 25 is that when the last digit (4 bits) of the communication ID is 0 or 8, the cordless handset 1 (12a) is the channel (1CH), the cordless handset 2 ( 1
2b) selects 31CH, slave 3 (12C) selects 25CH, and slave 4 (12d) selects 18CH. Hereinafter, depending on the communication ID, the slave unit 1 (12a) to the slave unit 4 (12) as shown in FIG.
The control channel 25 is fixedly selected according to step d). In this case, when all four control channels 25 are busy, a call is made in the same manner as when all channels are idle.

The callable channel of the call channel 25 is the caller of the call channel 25. In the caller side, the calling side sets the master unit No. 0 and the slave unit 1 after the control channel 24 is established.
(12a) is number 1, cordless handset 2 (12b) is number 2, cordless handset 3
(12c) is number 3 and slave unit 4 (12d) is number 4, and a call is made in a call channel group having a large call number.

As for the call channel 24, all the channels except the control channel 25 are used as the call channel 24 among the 40 channels available in the base unit 11 as shown in FIG. In order to prevent the collision of the communication channels in the system, all the slaves 12a to 12d have different communication channel groups.

That is, when the last digit (4 bits) of the call ID is 0 to 3, the cordless handset 1 (12a) is 1CH to 10CH,
The child machine 2 (12b) has 11CH to 20CH, and the child machine 3 (12)
c) is 21CH to 30CH, and the slave unit 4 (12d) is 31C
Select H-40CH. Below, the communication ID is 4 to 7,
In 8 to B and C to F, the respective slaves 1 to 4 (12a to 12d) select the respective communication channels 24 shown in FIG.

As described above, when the call channel 24 is divided into different channel groups for each of a plurality of slave units 1 to 4 (12a to 12d) by the communication ID, the quotient value obtained by dividing the total number of channels by the number of slave units is used. It suffices to assign each of the plurality of slave units 12a to 12d to a channel group corresponding to the quotient value. 40 of this example
In the case of channels, it may be assigned every 10 channels divided by 4 slave units. Further, in the present system, in the communication between the handset units, the communication is performed by the communication channel 24 of the calling side (master). It is designed not to make a call when all channels are busy.

In FIG. 4, the communication channel 24 is connected to the slaves 12a ...
In the case of having different channel groups (10CH in this case) for each 12d, the child device 1 (12a) and the parent device (11) have CH3.
Make an outside line call via the remote unit 2 (12b) and the remote unit 3
(12c) schematically shows a state in which an extension call is made via CH26.

FIG. 5 shows the relationship between the channel number of the call channel 24 and the frequency. The control channel is shown in FIG.
The last digit of the call ID is 4 or C, the control channel 25 is fixed to 12CH, 5CH, 36CH, 29CH, and the call channel can be the call channel 24 if the handset 1 (12a) is considered. Channel 1CH-1
For 0CH, the first call channel group 26a obtained by dividing 40 channels into 4 is divided into 1 to 3CH and the second call channel group 2
In 6b, 4th, 6th, and 7th CH, the third communication channel group 26
8 and 9CH in c are 1 in 4th call channel group 26d
0CH is selected.

With respect to the slave unit 2 (12b) as well, the first to fourth communication channel groups 26a to 26d have channels 11 and 13 respectively.
And 14,15CH and 16,17CH and 18,19,20
CH is selected, and the slave unit 3 (12c) and the slave unit 4 (12
Also in d), as shown in FIG. 5, the first to fourth communication channel groups 26a to 26d can be distributed in terms of frequency.

As for the relationship between the channel number and the frequency for the call channel 24, in FIG. 5, the channel numbers 1 to 3 have the lower frequencies, and the channel numbers 38 to 40 have the higher frequencies. 1 to 4
Calls are made in the call channel groups 26a to 26d, but since the channel numbers are made different, frequency interference and collision of the call channel 24 can be avoided.

The basic operation of the above-described protocol of the present invention will be described with reference to FIG.

FIG. 6 is a response diagram showing the basic operation of the present invention showing the response relation from the call to the call between the base unit 11 and the handset units 12a to 12d.

In FIG. 6, in this example, the control channels 25 fixed for each of the first to fourth channel groups 26a to 26d are in a monitoring state during standby, for example, the slave units 1 to 4
Any one of (12a to 12d), for example, handset 1 (1
When there is a call request (a) from the master device 11 from 2a), the master device 11
When the call response (b) is made from the handset 1 and the call execution (c) is made from the handset 1, the control channel 25 is shifted to and the call execution response (2) is made from the base 11 to the handset 1 (12a). After that, it shifts to the call channel.

When the channel is switched to the call channel 24, channel selection is performed in the empty channels of the first to fourth channel areas 26a to 26d, respectively, and no selection is made in the entire channel band.

That is, when the call channel 24 is entered, a call request (e) is made again from the handset 1 (12a) to the base unit 11, and in response to this, a call response from the base unit 11 to the handset 1 (12a). There is (to), and in response to the call execution (G) from the slave unit 1 (12a), the call is established on the master unit 11 side and the master unit 1
The call execution response (h) is made from 1 and the handset 1 (12a)
Then, the call is established, and after that, voice data (re) ~
The transmission of (nu) to (ru) to (e) ... Is performed alternately.

7 to 14 show an example of one form showing the relationship between the calling channel and the last channel, and FIG. 7 shows the initial state, and the first to fourth communication channel groups 26a to 26d in which 40 channels are divided into four. For example, when the last digit of the communication ID is 0 or 8, 1CH, 18CH, 25CH, 31 of the control channel 25 indicated by a dark square □
The CHs are fixed, and the respective 4CHs in total monitor the calling states of the respective channels 1CH to 40CH.

That is, in the monitoring state of the control channel 25, the above-mentioned fixed 1CH, 31CH, 25CH, 18 are fixed.
The CH monitors the calling state of the control channel 25 in parallel in a standby state as shown in FIG.

From such a standby state, the slave units 12a-12
For example, if a TALK call is made from the slave unit 1 (12a) to the master unit 11 in any one of d, assuming that the control channels 1CH, 25CH, and 31CH are busy and only 18CH is empty as shown in FIG. 18CH of 1 to 4
Since all the call states of 0CH are being observed, the call response is made by going to, for example, 4CH of the callable CHs which are empty channels, and the handset 11 (12a) and the base unit 11 shift to the control channel 25 by executing the call, After execution, as shown in FIG. 9, TALK connection with the slave unit (12a) is performed on 4CH and the master unit 1
The processing between the control channels 25 between 1 and the child device 1 (12a) is completed, and the communication channel 24 is entered.

In this system, a system is built in which extension lines can communicate with each other via the control channel 25 and the communication channel without using the master unit 11, so that, for example, FIG.
Considering the case where the slave unit 2 (12b) makes an extension call to the slave unit 4 (12d) as shown in 0, in this case, only 25CH of the control channel 25 is empty and the other 1CH, 18C.
If H and 31CH are busy, the process shifts from the control channel 25 to the process of the call channel 24, and as shown in FIG. 11, the call channel 24 of the caller (master) side slave unit 2 (12b) is, for example, 36CH. Connecting.

FIG. 12 shows a state in which only the CH 18 of the control channel 25 is empty and the base unit 11 makes a call to the handset unit 1 (12a). FIG.
FIG. 14 shows a case where the extension call of 2a) is connected by 4CH of the first channel area 26a, and FIG.
4 (12a to 12d) indicates an incoming state of an outside line (connected by CH 18).

[0047]

According to the digital cordless telephone apparatus and the method of assigning a call channel thereof according to the present invention, MCA by simultaneous use of call channels is possible and crosstalk is avoided.
It is possible to reduce the collision of call channels in the same system.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing one form example of a control channel used in the present invention.

FIG. 3 is an explanatory diagram showing one form example of a communication channel used in the present invention.

FIG. 4 is an explanatory diagram of an outside line and extension line communication state between the master unit and the slave unit according to the present invention.

FIG. 5 is an explanatory diagram of a method of dividing a communication channel and a method of allocating a control channel according to the present invention.

FIG. 6 is a call response diagram between a master unit and a slave unit showing one embodiment of the present invention.

FIG. 7A is an explanatory diagram showing a relationship between a call channel and a last channel of the present invention.

FIG. 8B is an explanatory diagram showing a relationship between a call channel and a last channel of the present invention.

FIG. 9C is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 10D is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 11 (E) is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 12 (F) is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 13G is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 14 (H) is an explanatory diagram showing the relationship between the calling channel and the last channel of the present invention.

FIG. 15 is a block diagram of a conventional DSS communication system.

FIG. 16 is a block diagram of a conventional cordless telephone system.

FIG. 17 is an explanatory diagram of a conventional communication channel and control channel between a master unit and a slave unit.

[Explanation of symbols]

2 ... Secondary modulator (spreading modulator), 11 ... Master unit, 12
a to 12d ... cordless handset, 19 ... microcomputer, 20 ... RF
Chip IC, 14, 15 ... Antenna for shared transmission and reception, 24
Call channel, 25 Control channel

Continued front page    (72) Inventor Tomohiro Tsuruhara             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation (72) Inventor Keisuke Koide             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F term (reference) 5K022 EE02 EE21 EE31                 5K027 AA12                 5K067 AA21 BB02 BB21 CC10 DD11                       EE02 EE10 FF02 HH11 HH22                       JJ12 JJ21

Claims (3)

[Claims] 1. A digital cordless telephone device having a master unit and a plurality of slave units connected by a plurality of channels for transmitting and receiving in a spread spectrum system, wherein the number of channels is divided by the plurality of slave units. A digital cordless telephone device characterized in that a value is obtained and assigned to each of the different channel groups corresponding to the quotient value for each of the plurality of slave units. 2. The digital cordless telephone device according to claim 1, wherein among the number of channels, the number of channels corresponding to the quotient value is fixed as a control channel and the others are communication channels. 3. A call channel allocating method for a digital cordless telephone having a master unit and a plurality of slave units connected by a plurality of channels for transmission and reception, wherein a quotient obtained by dividing the number of channels by the number of slave units. A method of allocating a communication channel for a digital cordless telephone device, characterized in that a value is obtained and is allocated to a different channel group corresponding to the quotient value for each of the plurality of slave units.