JPH04360433A - Telephone exchange - Google Patents

Abstract

PURPOSE:To use efficiently a spread code due to spread spectrum. CONSTITUTION:Stationary equipments 106-108 in the standby state use a control spread code so as to apply inverse spread processing to a reception signal. When a call takes place, a CPU 121 of a master set 102 refers to a memory 122 to select a control code for talking and informs it to a mobile set. Then the communication between the master set 102 and the mobile set is implemented by using the selected control code.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone switching device that is wirelessly connected to a plurality of mobile stations.

0002

2. Description of the Related Art Conventionally, when communicating between two parties using spread spectrum modulation, a spreading code assigned to each device in advance has been used.

0003

[Problem to be Solved by the Invention] However, in the conventional example described above, the number of spreading codes suitable for multiple access is small, so when attempting to configure a telephone switching device using spread spectrum, the number of fixed terminals that can be accommodated is limited. The problem was that it was getting smaller.

0004

According to the present invention, by selecting the spreading codes to be used, a large number of fixed stations can be accommodated with a small number of spreading codes.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a system implementing the present invention. 101 is a general subscriber line, PBX (private branch exchange)
This is an extension line, etc. 102 has one or more outside lines and 1
A main device that accommodates more than one line and has a switching function, 1
03-105 are telephones connected to the main device; 106-105 are telephones connected to the main device;
108 is a fixed machine connected to the main device, 109 to 116
is a mobile device connected wirelessly to a fixed device.

For example, the fixed machine 106 is connected to the mobile machine 109, 1
10, the fixed machine 107 manages the mobile machines 111 and 112, and the fixed machine 108 manages the mobile machines 113 to 116.

FIG. 2 is a block diagram of fixtures 106-108. A line interface 202 accommodates the extension 201 of the main device 102. Line interface 202 is connected to transmitter/receiver 204 via audio processing circuit 203 . Line interface 202, audio processing circuit 20
3. The transmitter/receiver 204 is controlled by the controller 205,
Furthermore, control data for the mobile device is input and output between the voice processing device 203 and the control unit 205 via the modem 206.

[0008] The spreading code used within the system is a ROM (
The control unit 205 transmits the spreading code determined by the main device 102 to the read-only memory) 207.
It reads from M207 and controls the transmitter/receiver 204.

Reference numeral 209 is an antenna for both transmitting and receiving radio signals.

FIG. 3 is a block diagram of mobile devices 109-116. A transmitter 302 and a receiver 301 are connected to a transmitter/receiver 304 via an audio processing circuit 303, and an antenna 3
05, it is connected to the fixed device wirelessly.

[0011] The control unit 306 reads the spreading code specified by the fixed device from the ROM 307, and transmits it to the transmitting/receiving unit 304.
control. Further, the control section 306 is connected to the audio processing circuit 303 via a modem 308, and also receives input signals from the keypad 309 and displays them on the display section 310. Power supply part 3
11 is a battery for a mobile phone.

The ROMs 207 and 307 store a plurality of spreading codes (
(including control spreading codes).

FIG. 4 shows the transmitter/receiver section 20 shown in FIGS. 2 and 3.
4,304. 401 indicates a transmitting section, and 402 indicates a receiving section. Audio processing circuits 203, 303
The transmission signal output from is input to the multiplier 403,
By multiplying the signal by the output of the local oscillator 404, it is output to the multiplier 407 on a carrier wave. The modulated signal is multiplied by a spreading code outputted from the spreading code generator 405 by a multiplier 407 to perform spread spectrum modulation. The signal is then transmitted from antennas 209 and 305 via amplifier 406.

Note that the spreading code generator 405 is controlled by the control sections 205 and 306 shown in FIGS. 2 and 3.

A signal received from antenna 408 is received by multiplier 410 via amplifier 411 . Multiplier 410 demodulates the spread spectrum modulation by multiplying the received signal and the spreading code output from spreading code generator 412 . The demodulated received signal is passed through BPF41
3, the carrier wave is removed by a demodulator 414, and sent to the audio processing circuits 203, 303.

On the other hand, the synchronization circuit 415 synchronizes with the received signal, and when synchronization is achieved, sends a synchronization establishment signal 416 to the control sections 205 and 306.

In this way, the spreading code generators 405, 412
is controlled by control units 205 and 306, and generates a specified spreading code at any time.

FIG. 5 is a diagram showing an outside call incoming sequence in the system of this embodiment. When the calling signal S1) is input to the main device 102 from the central office line 101, the main device 102
A CPU (central processing unit) 121 refers to the memory 122, searches for free spreading codes in the system, and determines the spreading code to be used. Then, the CPU 121 adds the code designation signal of the determined spreading code to the incoming call signal (S2) and sends it to the fixed devices 106 to 108. Note that the CPU 121 manages in the memory 122 whether each spreading code is in use or vacant.

The fixed devices 106 to 108 spread the incoming call signal (S3) containing the code designation signal of the spreading code designated by the main device 102 using the control spreading code set in advance in the ROM 207, and send the signal to the mobile device. Send to 109-116.

Mobile device 109 that received the incoming call signal (S3)
~116 reads the specified spreading code from the ROM 307 and sends the incoming call response signal (S4) and code switching completion signal (S5).
) is spread and transmitted to fixed devices 106-108. The fixed devices 106 to 108 that have received the code switching completion signal (S5) also send the code switching completion signal (S6) to the mobile devices 100 to 116.
), the bell ringing signal (S7) is spread with the specified spreading code and transmitted.

The mobile device 10 receives the bell ringing signal (S7).
9 to 116 ring a bell and, when off-hook, transmit an off-hook signal (S8) to the fixed devices 106 to 108. Fixed device 106-1 that received the off-hook signal (S8)
08 is an audio circuit on signal (S1
0) and sends a central line acquisition command (S9) to the main device 102. When the mobile devices 109 to 116 are on-hook, they send an on-hook signal (S12) and a call end signal (S13) to the fixed device 10.
6-108. When the fixed devices 106 to 108 receive the call termination signal (S13), they send a central line disconnection command (S14) to the main device 102 and end the call (S11).

FIG. 6 is a diagram showing an outside call incoming sequence in the system of this embodiment.

When mobile devices 109-116 are taken off-hook, they transmit a calling signal (H1) to fixed devices 106-108. The calling signal (H1) is spread using a control spreading code and transmitted. The fixed devices 106 to 108 despread the received signals using control spreading codes, and when receiving the calling signal (H1), they search the main device 102 for an empty code in the system and select the spreading code to be used. A code search command (H2) is sent to specify .

Main device 10 that received the code search command (H2)
2, after determining the spreading code to be used, the fixed devices 106 to
A code designation signal (H3) is sent to 108. Fixing machine 106
~108 receives the code designation signal (H3), spreads the code designation signal (H4) using the control spreading code, and transmits the code designation signal (H4) to the mobile device 1.
Send to 09-116. The mobile devices 109 to 116 that have received the code designation signal (H4) spread the code switching completion signal (H5) using the specified spreading code and send it to the fixed device 106.
~108.

When the fixed devices 106 to 108 receive the code switching completion signal (H5), they also transmit a code switching completion signal (H6) to the mobile devices 109 to 116, and then transmit an audio circuit on signal (H7). . On the other hand, a central line acquisition command (H8) is sent to the main device 102, and the central line is acquired (H9).
. The mobile devices 109 to 116 send a dial signal (H10), and when the other party answers, the mobile devices 109 to 116 enter a talking state (H11). Hereinafter, H12 to H14 are the same as S12 to S14.

In the system configuration diagram of FIG. 1, the main device 102
Although the fixing devices 106 to 108 are treated as separate devices, the fixing devices 106 to 108 may be built into the main device 102.

In this manner, when the CPU 121 of the main device 102 detects an incoming call from the outside line 101 or when the mobile device 10
When a call from 9 to 116 is detected via the fixed devices 106 to 108, one of the unused spreading codes is selected by referring to the spreading code usage table in the memory 122. Then, the CPU 121 notifies the fixed devices 106 to 108 (at the time of a call, to the fixed device that detected the call) of the number specifying the selected spreading code. The selected spreading code is registered in the usage status table as being in use.

On the other hand, when the call ends, the CPU 121 clears the status of the spreading code.

Further, the CPU 121 controls the switching section 120 to connect the extension and the outside line when any extension answers when a call is received, and when the called side of the outside line answers when a call is made.

In the standby state, the control unit 206 of the fixed devices 106 to 108 detects an incoming call from an outside line or an extension line via the line interface unit 202, and detects an outgoing call via the transmitting/receiving unit 204 and modem 308. I am doing it. In order to detect a call via the transmitter/receiver 204, the controller 20
6 reads the control spreading code from the ROM 205, sets it in the spreading code generator 412, and despreads the received signal in the uplink frequency band.

When the main unit 102 notifies an incoming call from an outside line or extension together with the selected spreading code number, the control units 205 of the fixed devices 106 to 108 control the control spreading code (control spread code for despreading). The spreading code may be different from the spreading code for
5, and the incoming call signal containing the selected spreading code number is spread via the modem 206 and transmitted from the antenna 209 to the downstream frequency band.

[0032] Then, the control section 2 of the fixators 106 to 108
05 reads the spreading code from the ROM 207 based on the number specifying the spreading code notified from the main device 102, sets it in the spreading code generator 412, and transmits the spreading code to the mobile devices 109 to 1.
Wait for a response from 16.

On the other hand, during the despreading of the uplink frequency band (frequency band that does not overlap with the downlink frequency band) using the control spreading code, calls made by the mobile devices 109 to 116 are sent to the modem 206.
When detected by the controller 2 of the fixed machines 106 to 108
05 requests the main device 102 to search for a spreading code. Upon receiving the spread code notification from the main device 102, the control unit 205 sets the control spread code in the spread code generator 405, spreads the selected spread code number via the modem 206, and makes a call. Notify the mobile device.

[0034] Then, the control section 2 of the fixing machines 106 to 108
05 sets the spreading code specified by the main device 102 in the spreading code generator 412, and waits for a response from the calling mobile device.

Regardless of whether it is an incoming call or an outgoing call, when a response signal spread with the specified spreading code is received from the mobile device, the control unit 205 sends a message indicating that the mobile device has responded. is notified to the main device 102, and then the communication state is established.

[0036] The control unit 306 of the mobile devices 109 to 116
In the standby state, the transmitting/receiving section 304 and modem 308 detect an incoming call, and the keypad 309 issues a call origination instruction.

During standby, the control unit 306 reads out the control spreading code from the ROM 308 and uses it in the spreading code generator 4.
06 to despread the received signal in the downstream frequency band. When the incoming call signal is detected by the modem 308, the control unit 306 reads out the spreading code from the ROM 307 based on the number specifying the spreading code included in the incoming call signal, sets it in the spreading code generator 405, and generates the response signal. is spread via the modem 308 and sent to the uplink frequency band.

Then, the control unit 306 similarly reads out the control spreading code from the ROM 307 and applies it to the spreading code generator 41.
2 and ready for control signals from fixators 106-108.

When there is an instruction to make a call using the keypad 309, the control unit 306 stores the control spreading code in the ROM 30.
7 is read out and set in the spreading code generator 406, and a calling signal is sent to the upstream frequency band via the modem 308. Similarly, the control spreading code is set in the spreading code generator 412, and responses from the fixators 106 to 108 are waited for.

When a spreading code is specified from the fixators 106 to 108, the control section 306 reads out the specified spreading code from the ROM 307, sets it in the spreading code generator 405, and sends a code switching signal via the modem 306. is transmitted to the uplink frequency band. Similarly, a specified spreading code is set in the spreading code generator 412 in preparation for reception of subsequent control signals and call voice signals.

In this way, in this embodiment, the spreading code is managed by the main device, so that the spreading code can be used effectively. In other words, the number of codes suitable for multiple access using code division is small. Therefore, if a spreading code is fixedly assigned to each fixator, only the same number of fixators as there are usable spreading codes can be provided in the system.

On the other hand, in this embodiment, since a spreading code is assigned to each fixed station during a call, more fixed units than usable spreading codes can be provided in the system.

[0043] When all the spreading codes (control spreading codes) are in use when a mobile device 109 to 116 makes a call, the CPU 121 of the main device 102 notifies the fixed device that detected the call. The control unit 30 of the fixation device that received the notification
6 spreads the busy signal using a control spreading code and sends it to the downstream frequency band. The control unit 306 of the calling mobile device that has received the busy signal sends out a busy tone via the receiver 301 .

[0044] The control spreading codes of the transmitting sections of the fixed devices 106 to 108 and the control spreading codes of the receiving sections of the mobile devices 109 to 116 are the same, and the control spreading codes of the receiving sections of the fixed devices 106 to 108 are the same. The control spreading codes of the transmitters of mobile devices 109 to 116 must be the same, but the control spreading codes of the transmitters of mobile devices 109 to 116 must be
108. The control spreading codes of the transmitter and receiver of the mobile devices 109 to 116 may not be the same. The same applies to designated spreading codes for telephone calls.

The timing for switching from the control spreading code to the specified spreading code may be such that the control spreading code is switched to the specified spreading code after the code switching completion signal is communicated using the control spreading code and before the call is made.

As described above, in this embodiment, the main device 102 and the mobile devices 109 to 116 perform despreading using the control spreading code in the standby state. Then, when a call occurs, the main device 102 spreads a number specifying the spreading code to be used for the selected call using the control spreading code and notifies the mobile device. Then, the control spreading code is switched to the selected spreading code before the start of the call, and a transition is made to the call state.

[0047] After a call between one set of fixed and mobile units is transferred to a communication state, the other fixed and mobile units that are in an empty state
Communication using the control spreading code becomes possible, and other calls using other spreading codes can be connected.

[0048]

As explained above, according to the present invention, spreading codes can be used effectively.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a fixing machine according to an embodiment of the present invention.

FIG. 3 is a block diagram of a mobile device according to an embodiment of the present invention.

FIG. 4 is a block diagram of a transmitting/receiving section according to an embodiment of the present invention.

FIG. 5 is a sequence diagram when a call is received in the system according to the embodiment of the present invention.

FIG. 6 is a sequence diagram when a call is made in the system according to the embodiment of the present invention.

[Explanation of symbols]

100 Main device 106 Fixed machine 109 Mobile device

Claims (2)

[Claims] 1. Selection means for selecting one of a plurality of spreading codes; notification means for wirelessly notifying a mobile device of the selected spreading code; and a call audio signal from the notified mobile device. and exchanging means for despreading and exchanging using the selected spreading code. 2. The selection means has a storage means for storing whether each of the plurality of spreading codes is in use, and the selection means can select a spreading code that is not in use by referring to the storage means. 2. A telephone switching device according to claim 1, characterized in that: