JP3500529B2 - Connection device for digital cordless telephone equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of connecting devices connected to an extension bus from a main unit of a home telephone or a key telephone device, and these connecting devices and TDMA / TDD.
The present invention relates to a connection device in a digital cordless telephone device including a plurality of slaves connected by a wireless line using a system (time division multiple access time division bidirectional communication system).

[0002]

2. Description of the Related Art In a conventional digital cordless telephone system, when a plurality of cordless handsets are used at the same time, each of a plurality of connection devices connected to a main device independently controls a frequency and a transmission / reception slot. It was There are two control frequencies (control channels) used by the connection device for the control frame (superframe), and the signals of almost the same content are transmitted, but the control signals of the first control frequency f1 and the second control frequency f2 are used. Are sent at different timings. That is, after the control signal of the first control frequency is output, the control signal of the second control frequency is output after a certain delay. This is repeated for each control frame (superframe). Conventionally, the difference in the transmission timings of the control signals of these two control frequencies is collectively fixed by the digital cordless telephone device, or arbitrarily determined for each connecting device, so that the connecting devices of the same digital cordless telephone device are The control signal transmission timings of both the first control frequency and the second control frequency may be the same.

[0003]

In the above digital cordless telephone device, the time from the transmission of the control signal of the first control frequency by the plurality of connection devices to the transmission of the control signal of the second control frequency. Even if the intervals are the same, if the control frames are transmitted while changing the timing of outputting the control signal of the first control frequency f1 between the connected devices, they do not overlap at all control frequencies. Figure 5
This is shown in the signal relationship between the connection devices CS01 and CS02. However, the control signals of the first control frequency may overlap with each other as time elapses due to a difference in clock accuracy between the connection devices. At this time, if the connecting devices are the same in the transmission timing difference between the control signal of the first control frequency and the control signal of the second control frequency as described above, if the control signals of the first control frequency overlap. Inevitably, the control signals of the second control frequency also overlap. In this way, if radio wave interference occurs in which control signals of two control frequencies overlap, accurate data communication cannot be performed. Connection device C in FIG.
S01, CS03, CS (0L) shows a state where radio waves interfere with each other. An object of the present invention is to eliminate the above-mentioned inconvenience, and even if the transmission timing of the control signal of the control frequency between the connection devices is deviated for some reason, at least one control channel is provided between the connection device and the slave unit. The purpose of the present invention is to provide a connection device capable of transmitting and receiving by using.

[0004]

The present invention has the following constitution in order to achieve the above object. (1) A plurality of connection devices connected to an extension bus from a main device of a home telephone or a key telephone device or a main device accommodating a line, and a plurality of connection devices connected to these connection devices by a wireless line using a TDMA / TDD system In a digital cordless telephone device equipped with a slave unit of the
A connection device comprising means for presetting a difference in transmission timing of two control signals for each connection device so that at least one of the control signals does not cause radio wave interference between the connection devices. (2) As means for presetting the difference in the transmission timings of the two control signals for each connecting device, a different number is set for each connecting device connected to the main device,
The connection device according to the first item, wherein the transmission timing difference corresponding to this number is selected.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a control signal transmission timing chart according to an embodiment of the present invention, FIG. 1B is a control signal transmission timing chart, and FIG. 7 is a timing chart in which a slave receives a control signal. FIG. 2 shows TDMA / TD composed of transmission / reception slots.
FIG. 3 is a diagram showing a D frame, and FIG. 3 is a configuration diagram of a home telephone using the digital cordless telephone device of the present invention.
FIG. 4 is a block diagram of the connection device. FIG. 5 is a conventional control signal transmission timing chart. 1 is the main device, 2
Is a connection device (CS1 to L), 3 is an antenna, and 4 is a slave unit (PS). 10 is a central office switch, 11 is a line (I
SDN line or telephone line, hereinafter called ISDN line),
12 is an extension bus, 14 is a telephone connected to the extension bus,
Reference numeral 20 denotes a digital cordless telephone device including a part of the main device 1, a connection device 2 and a slave unit 4 group. Reference numeral 21 is an extension bus connector, 23 is a bus data transmitting / receiving unit, 24 is a phase corrector, 25 is a baseband LSI, 26 is an ADPCM-CODEC in the baseband LSI 25, and 27 is a T.
DMA / TDD processing unit, 28 is a π / 4QPSK modem,
Reference numeral 29 is a wireless unit, 30 is a bus, 31 is a CPU, 32 is a reference clock generation unit, 33 is a reference timing generation unit, 34 is a work switch for setting the number of the connection device 2, 35 is a memory, and 36 is a connection device. ID for storing CS-ID of 2
ROM and 37 are power supplies. TDMA / TD shown in FIG.
The D frame is 5 mS, and is composed of 4 slots for transmission and 4 slots for reception. In principle, the connection device 2 and the handset 4 use the same carrier wave, and four calls can be simultaneously performed.

First, the configuration of the home telephone according to the present invention will be described with reference to FIG. Main device 1 is a central office switch 1.
ISDN line from 0 (or telephone line, same below) 11
Are housed. The connection device 2 and the telephone set 14 are connected to the main device 1 through an extension bus 12. Under the control of the main unit 1, the slave unit 4 makes an outgoing call to the ISDN line via the connection unit 2 connected by a wireless line and receives an incoming call from the ISDN line. A part of the connection device 2, the slave 4, and the main device 1 for controlling the wireless line, that is, a part excluding the control of the telephone is referred to as a digital cordless telephone device 20.

Next, the operation of the connection device 2 of the present invention shown in FIGS. 3 and 4 will be described with reference to various signals shown in FIGS. Various signals are transmitted from the main device 1 to the connection device 2 through the extension bus 12. These signals are configured in multiframe format. The multi-frame is a basic frame N that is composed of frame number data, B channel data corresponding to each connection device, D channel data for control, etc. at the beginning.
It consists of individual pieces. The multi-frame signal supplied from the main unit 1 to each connecting unit 2 via the extension bus 12 reaches the bus data transmitting / receiving unit 23 through the bus connector 21. The bus data transmitter / receiver 23 generates a multi-frame clock MFCK from the input multi-frame signal and outputs it to the reference timing generator 33. Also, it generates a basic frame signal of 8 kHz and outputs it to the reference clock generator 32 and the phase corrector 24.

The reference clock generator 32 is a PLL circuit, and a reference clock generator 32 is used to adjust 8 kHz used as a PCM synchronizing signal between the baseband LSI 25 side and the phase corrector 24 to the basic frame signal 8 kHz from the bus data transmitter / receiver 23. Oscillation control of clock 19.2 MHz. In the baseband LSI 25, this reference clock 19.2
After receiving the supply of MHz, the frequency is divided to 8 kHz and returned to the reference clock generator 32. Reference timing generation unit 3
3, the reference clock 19.2 MHz input from the reference clock generator 32 is divided, and the TDMA / TDD processor 2
The transmission / reception slot timing of 625 μS, which is the synchronization signal shown in FIG.
CPU with 5ms TDMA / TDD frame timing
Output to 31. The CPU 31 also generates a superframe interval of 130 mS from the timing of 5 mS.

Multiframe control data (D channel) from the extension bus 12 is output to the bus 30 toward the CPU 31. Based on this control data that has arrived, the CPU 31 performs various controls and also controls the transmission of control data that is transmitted from the connection device 2 of its own to the main device 1. Further, the B channel data (voice data or data for data communication) in the multi-frame is sent from the bus data transmitter / receiver 23 to the phase corrector 24 in synchronization with the reference frame timing 8 kHz. In addition, one connection device 2 from the multi-frame,
It takes in the B channel data assigned to itself.
In the phase corrector 24, this is replaced (synchronized) with the reference timing (PCM synchronization signal) 8 kHz on the side of the baseband LSI 25 supplied from the baseband LSI 25, and ADPCM-CODE in the baseband LSI 25 is synchronized.
It has been sent to C26. Furthermore, in the TDMA / TDD processing unit 27, 32 bits from this ADPCM-CODEC 26
625 generated by the reference timing generation unit 33 by converting each data of kbps into a burst signal of 384 kbps.
Assigned to one of the transmission slots indicated by CS1 in FIG. 5 created at the slot timing of μS, and the next π / 4QPSK
Send to modem 28. The π / 4QPSK modem 28 modulates the input signal and sends it to the radio unit 29. Radio unit 29
Converts this signal into a transmission frequency and emits it as a radio wave from the antenna 3.

On the other hand, the radio unit 29, which has received the radio wave emitted from the slave unit through the antenna of the connection device 20, carries out the frequency conversion and then the π / 4QPS in the baseband LSI 25.
It is sent to the K modem 28. The signal demodulated by the π / 4QPSK modem 28 is arranged at the receiving slot position corresponding to the transmitting slot position as shown in FIG. TDMA
In the / TDD processing unit 27, contrary to the transmission data, 384 kb
The speed is converted from ps to 32 kbps, and the received data in the unique receiving slot position is detected, and further ADPCM-C
The ODEC 26 converts the data into 64 kbps data and sends the converted data to the phase corrector 24. Phase corrector 2
In 4, the received data from the baseband LSI 25 is transferred to the bus data transmitter / receiver 23 with the PCM synchronization signal (basic frame signal) on the side of the bus data transmitter / receiver 23 replaced with the timing of 8 KHz. The CPU 31 inserts the received data from the phase corrector 24 into the position of the B channel corresponding to its own connecting device and the control data from the CPU 31 into the D channel in the bus data transmitter / receiver 23 to synchronize with the received multiframe. A transmission multi-frame (not shown) is created and sent to (the transmission line of) the extension bus 12. In this way, in the digital cordless telephone device 20, each connection device 2 performs transmission / reception with the child device 4 connected by the wireless line.

A specific example of the present invention will be described with reference to FIG. The control frame (superframe timing) transmitted during standby is 130 mS (TDMA / TDD frame 5 mS × 26). The connection device 2 sets the time for transmitting the control signal of the first control frequency and then transmitting the control signal of the second control frequency as shown in FIG. That is, the connection device 2 (CS1) transmits the control signal of the second control frequency,
5 ms from the time when the control signal of the first control frequency is transmitted
It is sent after x8 has passed (that is, the ninth frame). The connection device 2 (CS2) sends the control signal of the second control frequency to the first control signal.
5mS x 9 from the time when the control signal of the control frequency of
It is transmitted later (that is, the 10th frame). The same is set thereafter. Finally, the connection device 2 (CS5) sends the control signal of the second control frequency after 5 mS × 5 has elapsed from the time of sending the control signal of the first control frequency (that is, the 13th frame).

In the connection device 2, the above-mentioned sending control is performed as follows. A number different from those of other connecting devices is set by the work switch 34 of each connecting device 2. As an example, the CS1 number of the connection adapter 2 is 9. The CPU 31 detects that CS1 of its own connection device 2 is set to number 9, controls the TDMA / TDD processing unit 27, and outputs 5 m from the time when the control signal of the first control frequency f1 is transmitted.
After S × 8 (9th TDMA / TDD frame)
Control signal of the second control frequency. Next, the CS2 number of the connection adapter 2 is set to 10. The CPU 31 detects that CS2 of its own connection device 2 is set to the number 10, controls the TDMA / TDD processing unit 27,
5 from the time when the control signal of the first control frequency f1 is transmitted
After the lapse of mS × 9 (10th TDMA / TDD frame), the control signal of the second control frequency is transmitted. Thereafter, in the same manner, the CS (L) of the connection adapter 2 determines the number such as (L + 8) to determine the difference between the control signal transmission timings of the first control frequency f1 and the second control frequency f2. I have decided.

Next, referring to FIG. 1 (2), C of the connection device 2
S1 and CS2 indicate a normal state in which the control signals of the first control frequency f1 and the control signal of the second control frequency f2 are different in transmission timing. Next, for some reason, the connection device 2
First control frequency f of CS1, CS3, and CS (L) of
The case where the control signals of 1 are overlapped is shown. But,
Here, since the transmission timings of the control signal of the first control frequency f1 and the control signal of the second control frequency f2 are different, at least the second control frequency f is set between the connection devices.
Control signals of 2 do not overlap. On the contrary, when the control signals of the second control frequency f2 overlap between the connection devices, the control signals of the first control frequency f1 do not overlap between the connection devices.

In FIG. 1 (3), the PS of the child device 4 is provided around the connection device 2 (CS (L)) which is sending the control signal.
When (1) and PS (2) are arranged, PS (1), which alternately receives the first control frequency f1 and the second control frequency f2 every 400 mS, is the first control frequency f1.
If a control signal is received, a response signal is transmitted after 2.5 mS. Thereafter, the CS (L) and PS (1) start transmitting / receiving control signals. Next, if both PS (1) and PS (2) send response signals to the control signal of the same control frequency at the same time and a radio wave trouble occurs, both PS of the slave units
Since different retransmission timings are defined in advance in (1) and PS (2), the child device whose transmission timing arrives earlier responds to the connection device.

In FIG. 1, for the sake of explanation, each connecting device simultaneously transmits the control signal of the first control frequency, but in reality, the timing of transmitting the control signal of the first control frequency is not the same. Sending out differently. According to the present invention, by transmitting the control signal at the time of standby while preventing the radio wave interference,
It is possible to reliably perform operations such as transmission, reception, and handover.

[0016]

The plurality of connecting devices of the digital cordless telephone device of the present invention are arranged so that the timings at which the control signal of the first control frequency and the control signal of the second control frequency are transmitted are different from each other. Even if one of the control signals overlaps, the other control signal does not overlap, and it is possible to always maintain a communicable state with the child device.

[Brief description of drawings]

FIG. 1 is a timing chart (2) of transmitting a control signal, which is an embodiment of the present invention, a timing chart (3) of transmitting a control signal, and a timing chart when a slave unit receives a control signal of a connection device.

FIG. 2 is a TDMA / TDD composed of transmission / reception slots.
Illustration showing the frame

FIG. 3 is a configuration diagram of a home telephone using the digital cordless telephone device of the present invention.

FIG. 4 is a block diagram of a connection device.

FIG. 5 is a conventional control signal transmission timing chart.

[Explanation of symbols]

1 main device 2 connection devices (CS1-L) 3 antennas 4 cordless handsets (PS) 10 telephone exchanges 11 ISDN line 12 extension buses 14 telephones 20 Digital cordless telephone device 21 Extension bus connector 23 Bus data transceiver 24 Phase corrector 25 Baseband LSI 26 ADPCM-CODEC 27 TDMA / TDD processing unit 28 π / 4 QPSK modem 29 radio section 30 bus 31 CPU 32 Reference clock generator 33 Reference Timing Generation Unit 34 Engineering Note Switch 35 memory 36 ID-ROM 37 power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-188823 (JP, A) JP-A-9-149459 (JP, A) Second Generation Cordless Telephone System Standards, Japan, Japan Association of Radio Industries and Businesses , June 25, 1996, 2nd edition (revised-2), page 59 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04B 7/24-7/26 H04Q 7/00-7 / 38

Claims (2)

(57) [Claims] 1. A plurality of connecting devices connected to an extension bus from a main device of a home telephone, a key telephone device or a main device accommodating a line, and these connecting devices and TDMA / TD.
In a digital cordless telephone apparatus equipped with a plurality of cordless handsets connected by a wireless line using the D system, a difference in transmission timing between two control signals having different frequencies transmitted at superframe timing is calculated for each connection device. A connecting device, characterized in that the connecting device is provided with a means for presetting it so as to be different from each other so that at least one of the control signals does not cause radio wave interference between the connecting devices. 2. As a means for presetting the difference in the transmission timings of the two control signals so as to be different for each connection device, a different number is set for each connection device connected to the main device, and this number is handled. 2. The connection device according to claim 1, wherein the selected transmission timing difference is selected.