JPH08298678A - Radio telephone exchange system - Google Patents

Abstract

PURPOSE: To digitize a radio transmission line between a communication terminal and an exchanging device, to improve privacy, noise resistance and the compatibility of a digital exchange system with a telephone exchange system. CONSTITUTION: A digital radio transmission line(DRTL) connects a communication terminal and an exchanging device 200 through a radio transmission line. The DRTL is constituted of a format capable of directly accessing highways 260, 261. A modem 210 in the device 200 directly reads out a sound signal modulated to a digital, signal in an optional time slot on the highway 260 from a buffer memory 215, sends the read signal to the DRTL as a radio signal, temporarily stores a sound signal received through the DRTL in a buffer memory 216, and then stores the sound signal in an optional time slot on the highway 261, so that the device 200 can optionally control the connection of a call.

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to voice, data, images, etc.
Related to the telephone exchange system for exchanging and connecting information of
A communication terminal device such as a telephone and a data terminal device,
Wireless transmission lines between switching devices, and
Wireless telephone switching system using the established transmission line as a digital transmission line
Regarding the system. Taking a wireless telephone system as an example,
Car phones and wireless phones have been put to practical use. Before
In the case of
Therefore, phase modulation and frequency modulation are adopted. For example,
"New edition, mobile communication system" published by Kagaku Shimbun (1979)
Issued May 10th (hereinafter referred to as "Reference 1") No. 23
An overview can be found in Sections 9-260. The latter is generally
In general, a cable is pulled from the telephone office to the subscriber's premises.
It is wireless in the subscriber's home,
Number modulation is often used. (Reference 1, No. 294
Item-301) In addition, it is a test that is relatively close to the usage environment targeted by the present invention.
Although various systems have been tried, the phase modulation method was adopted.
Since the exchange is also a crossbar system, it is confidential and durable.
The noise and anti-jamming problems have not been solved. (Reference sentence
(Item 1, item 291 to item 294) Digital exchange
As a mobile radio system adopting the system, for example, Japanese Patent Laid-Open No.
59-58927 publication etc. are mentioned. [0003] The above-mentioned prior art is the replacement
The wireless transmission path between the device and the communication terminal device is of analog type.
Since it is used, there are problems with confidentiality, noise resistance, and interference resistance.
Yes, and telephone exchanges that use the digital exchange method.
The compatibility with the replacement system is not very good.
It was An object of the present invention is to provide an analog wireless system as described above.
In order to solve the problems of the wireless telephone exchange system used,
To provide a good wireless telephone exchange system,
More specifically, the network between the telephone communication terminal equipment and the exchange equipment.
Enables earlessness, improves confidentiality and noise resistance,
In addition, a telephone exchange system that uses the digital exchange system.
Wireless telephone exchange system with improved compatibility
Is to provide. In addition, in the exchange device,
Terminals according to traffic, not depending on the number of line terminals
If you have an interface,
A number of economical configurations can be achieved by appropriately controlling the configuration.
Wireless telephone exchange system that enables exchange operation of existing wireless terminals
It is to provide the system. In addition, communicate with wireless terminals
When connecting and exchanging the other party, there is no restriction on the connection route etc.
Flexible system configuration allows for switching connections and system setup.
Wireless telephone exchange system for easy installation and setting changes
To provide a simple configuration. And the wireless end
Even if the end is moved and used in various places, the problem mentioned above
The points have been resolved and the above-mentioned problems can be satisfied.
Providing an easy-to-use distributed wireless telephone exchange system
To serve. [0004] To solve the above problems,
In addition, the wireless telephone system of the present invention includes a plurality of wireless terminal devices.
And a switching device for switching and connecting a call from the wireless terminal device.
And a plurality of wireless terminals.
Each of the end devices has a transmitter and an analog from the transmitter.
A first modulator for digitally modulating the audio signal, and
Restores the digitally modulated audio signal to an analog audio signal.
A first demodulator for adjusting and an analog from the first demodulator
From a receiver that outputs a voice signal and the first modulator
Of the digitally modulated voice signal to the switching device
The digitally modulated voice signal from the switching device
A first wireless transceiver for sending to the first demodulator
The exchange device receives a digitized voice signal.
Transmission high with multiple time slots accommodated
Way and receive highway, the transmit highway and receive
The time slot of the highway is controlled to control the wireless terminal device.
Switch means for switching and connecting the call from the
Interface connected to Eway and Receive Highway
Means and a predetermined time slot of the transmission highway.
Means for extracting the digital audio signal in the
A second modulator for digitally modulating the signal from the output means;
Digitally modulated from the plurality of wireless terminals
Second demodulation for demodulating a voice signal to a digital voice signal
And a receiver for receiving the demodulated digital audio signal.
Sending means for sending in a predetermined time slot of a way
Interface means, and the interface hand
Digital radio between the wireless terminal device and the
A second transceiver for transmitting and receiving signals, the interface
The audio signal digitally modulated by the
To the digital device from the wireless terminal device.
Send the modulated audio signal to the interface means
A second transceiver and a transmission highway of the switching device
Incoming highway time slot and switch means
And a control means for controlling the interface means. With the above configuration, the communication terminal device and the exchange device
It enables wireless communication between users and improves confidentiality and noise immunity.
A telephone that has been upgraded and uses the digital switching system.
It is possible to improve compatibility with exchange systems.
Become. [Example] 1. SUMMARY OF THE INVENTION The present invention relates to a communication terminal device and a time division multiplexing exchange device.
Introduced spread spectrum modulation and demodulation technology to the information transmission of
Install the spread spectrum modulator / demodulator in the central controller of the exchange.
By controlling the position of the storage
System, especially the wireless switching system
Things. Connection between terminal equipment and switching equipment in the office
When making wireless, the terminal device is not in use.
You can think that it is stationary, and you are communicating in mobile radio etc.
We do not consider the problems caused by the movement of the terminal device. Well
The distance between the terminal device and the antenna on the exchange side is also
Installed in each room or a leaky coaxial cable on the ceiling, etc.
It is possible to make them almost even by installing them.
Therefore, the terminal device side compensates for the difference in distance from the antenna.
Spread spectrum without controlling the transmission power for
Communication becomes possible. In addition, transmit from one antenna
The reach of radio waves is not in the same room or on the same floor.
In addition, since it can be limited to a relatively narrow range, weak radio waves are used.
Available and effective use of radio waves. Spect
Pseudo-noise codes for Lamb spreading modulation and demodulation
Considering the elephant, the number of terminal devices in the same system is too large.
On the other hand, on the other hand, regarding the difficulty of signal decoding, military communication
It is considered that a high degree of confidentiality like in
Therefore, a relatively simple code can be used. That is,
The spectrum spread modulator / demodulator can be simplified. Based on such a premise, the present invention provides a terminal device.
Device and the switching device, respectively,
Set up a transceiver including a noise code generator, antenna, etc.
For example, whether the reach of the radio waves transmitted from each antenna
Within a certain area, the number of pseudo-noise codes that do not overlap is reduced.
It is given to each terminal device at least. In the case of originating from the terminal device, the terminal device
Is the spectrum with the pseudo-noise code given to the own terminal device.
Sends out the spread-call modulated call signal to the demodulator of the exchange.
In this case, there is a pseudo-noise code that captures this signal.
Or the information transmitted by this code is stored in the switching device.
The central control unit recognizes the calling terminal device.
Separate. The central controller sends the pseudo-noise code of the calling terminal.
Set the spread spectrum modulator on the switching equipment side to
Set the downlink channel to the end device. In the case of an incoming call to the terminal device, in the exchange device
Since the called number is sent to the central control unit of
The called terminal device is identified from the number, and the corresponding switching device side
The pseudo-noise code of the spread spectrum modulator and demodulator is
Set it to the code of the call terminal and set the control signal of the terminal to this
Call the called terminal by sending it on the channel.
put out. In the case of making a call and the case of receiving a call, the above description has been given.
After setting the channel between the terminal device and the switching device depending on the method
For example, for voice, 8 bits of 8000 samples / second
Companded PCM code is a pseudo-noise code given to a terminal device
No. is transmitted and received after spread spectrum. In this way
A communication system with high confidentiality and strong anti-jamming can be realized.
It In addition, direct sequence and frequency
Several modulation methods are considered, such as several hopping
However, the present invention does not depend on the modulation method. FIG. 4 shows an example of a communication system in a building.
Then, a cable 400 from the outside, for example, a local line comes in.
Place the main exchange unit 300 on each floor,
The exchange device 200 is installed, and the main exchange device 300 and each child exchange device are installed.
The conversion device 200 includes a cable 600, for example, an optical fiber cable.
-, Connected to each other via node device 610
I have. The main exchange apparatus 300 and the child exchange apparatus 200 are
Antenna 500, such as a leaky coaxial cable
It The terminal device 100 is a combined voice / data terminal device.
And a switching device 2 through the antenna 500.
00 or 300 is wirelessly connected. this
In the communication system, the switching device 200/300 and the end
Since the wireless connection between the end devices 100, installation work
Installs the switching device 200/300 and the node device 61.
0, connection with external cable 400, antenna 5
00 laying and connection is sufficient, and the switching device 200/300
No wiring is required between the terminal device 100 and the terminal device 100. further
Optical fiber is adopted for the cable 600 and time division multiplexing is performed.
If so, there is no need to distribute a large amount of cables,
Things become very easy. FIG. 1 and FIG. 2 are main exchange devices in FIG.
The apparatus 300 or the child exchange apparatus 200 is related to the present invention.
FIG. 3 shows the first and second embodiments of the part, and FIG.
An example of the terminal device 100 is shown. Hereinafter, using FIG.
The first embodiment will be described in detail. 2. a First Embodiment In this embodiment, as shown in FIG.
Depending on the hicks, it is possible to change the number of simultaneous calls / communication
Since the demodulation device 210 handles information for only one line, it is slow
There is a feature that works with. With the terminal device 100 in FIG.
The information between the switching device 200 or 300 is
RATING SERVICE DIGITAL NETWORK
(ISDN: Integrated Services Digital Network)
6 for voice or data, which is being standardized as
4 kb / s channel B and 16 for data and signals
It shall consist of channel D of kb / s. Figure 5 shows
On the highway in the switching equipment and between the switching equipment and the terminal equipment.
It shows the relationship between the above channels B and D on the transmission path.
is there. FIG. 5A shows a case where the voice is mainly used and the terminal device is B.
When exchanging + D information, Fig. 5 (b) shows ISDN.
Information of B + B + D which is considered to become the standard of
This is the case. The frame shown in FIG. 5 (a) means 8000 per second.
1 sump, where audio is sampled at sample rate
It is equivalent to 125us in the time of one minute. In this frame
n time slots are time-division multiplexed, one
Each time slot, eg TS0, consists of 8 bits
ing. When sending to the transmission line to the terminal device,
Add 2 bits as a channel and expand it temporally to 8
It is transmitted at a speed of 0 kb / s. Sent from the terminal
On the other hand, the information that came in has 2 bits of the D channel removed.
At a specified tie on the highway, compressed in time
Inserted into the Musslot. In addition, FIG.
In the case of + B + D, the signal speed with the terminal device is 144 kb
/ S. In the figure, B + B is the time slot
Although TS0 and TS1 are assigned, they are not always adjacent
Not limited to imslots, and different highways
There is also a possibility. In this embodiment, for simplification, as shown in FIG.
The case will be described. First, when the call / communication state is not established, as shown in FIG.
In the switching device 200/300, the central controller 24
0 is the modulation / demodulation device 210 via the signal reception / distribution device 230.
To prepare for call detection. That is, the central controller 240
Specifies the vacant modulator / demodulator 210, and if the preamble
If the period is adopted, the modulation / demodulation device 210 is simulated.
Call to the noise code generator (hereinafter referred to as PN generator) 213
A pre-allocation assigned to the terminal device 100 to be detected
Bull code and pseudo noise code (hereinafter referred to as PN code) specified
Then, the spread demodulator 21 uses the preamble code for synchronization acquisition.
Instruct to drive 2. For calling detection of multiple terminals
At this time, the central control unit 240 controls the modem unit 210.
Allow sufficient time for the demodulator to acquire synchronization,
Preamble code of the terminal device 100 that may make a call
And PN code are sequentially switched to drive, and call origination is detected.
Good. In this case, a plurality of modulation / demodulation devices 210 are used, and at the same time
It is also possible to perform multiple call detections. That is, in the known switching device, the central control system is used.
The device spatially scans the line interface circuit
On the other hand, in the exchange device of the system of the present invention,
The central controller 240 uses the modulator / demodulator 210,
The preamble code and PN code of the dispersion demodulator 212 are deleted.
Next, switch and scan, and issue when synchronization acquisition is performed.
It will be regarded as a call. In addition, given to the same terminal device
PN code goes up (transmission from terminal equipment to switching equipment)
And when going down (transmission from the exchange to the terminal),
In this case, the PN code set in the spread demodulator 212 is
It becomes the code for going up. Next, also in the terminal device 100,
When not in a call / communication state, spread demodulation in FIG.
Only the generator 112 is generated by the PN generator 113.
Also, the synchronization acquisition operation is performed by the downlink preamble code of the own terminal device.
And prepare for reception. 2. a. 1 Calling operation First, the calling operation of the terminal device will be described with reference to FIGS.
-A description will be given using a chart. # M1 terminal device 1 in FIG.
When the handset is raised at 00 (601 in FIG. 6), FIG.
This is detected by the control device 140 shown in (not shown).
The control device 140 receives the P signal via the interface circuit 150.
The N generator 113 outputs the upstream preamble code to the spread modulator.
111, and the spread modulator 111
Sends a rumble signal. Upward Prian of own terminal device
Preamble signal spread-spectrum-modulated with bull code
The signal is amplified to a predetermined power by the transceiver 120,
It is sent from the tenor 130 (602 in FIG. 6). Preamble transmitted from antenna 130
1 is received by the antenna 500 of FIG.
It is amplified by 220 and spreads all the modems 210.
It is input to the adjuster 212. Now, No. 1 modulator / demodulator 21
0 spread spectrum demodulator 212 causes central controller 240 to detect call origination.
By the control for outgoing, the # m1 calling terminal device goes up
If it is set to the preamble code, the sync
Path 214 is activated and acquires synchronization (FIG. 6, 611). In the exchange device 200/300, No. One change
When the synchronization is acquired from the synchronization circuit 214 of the demodulator 210,
The signal to say is transmitted through the signal receiving / distributing device 230 to the central system.
Sent to the control device 240. The central control unit 240 is No.
The spread demodulator 212 of the 1-modulation-demodulation unit 210 uses the # m1 terminal device.
Knowing that it has been synchronized with the upstream preamble code of
# M1 It is identified that the terminal device has made a call (FIG. 6, 61
2). The central control unit 240 has a No. 1 modulation / demodulation equipment
# M1 terminal device 1 with respect to the spread modulator 211 of the device 210
00 downlink preamble code and PN code to PN code
It is set in the generator 213 (FIG. 6, 613). By this
Therefore, the spread modulator 211 transmits and receives the downlink preamble signal.
It is transmitted through the receiver 220 and the antenna 500. # M1 The calling terminal device 100
The amble signal is passed through the antenna 130 and the transceiver 120
Received by the spread demodulator 112 and controlled by the synchronization circuit 114.
Period (FIG. 6, 603). As a result,
# M1 terminal device 10 confirms that the downlink is synchronously acquired.
Since 0 can be confirmed, the spread spectrum code of the uplink
Is switched from the preamble code to the PN code for communication,
After that, the synchronization circuit 114 continues the synchronization tracking. Prior to switching
Then, the terminal device 100 multiplies the switching signal on the preamble signal.
And sends it to the spreading demodulator 212 of the switching device 200,
Spreading modulator 111 on the storage side and spreading demodulator 21 on the switching device side
2 switches to PN code while synchronizing (Fig.
6, 604, and FIGS. 6, 615). In the switching device 200, the spreading demodulator 212 is
Switching from preamble code to PN code for communication
Accordingly, the terminal device 100 also outputs the downlink preamble signal.
After confirming that synchronization has been acquired, switch to the downlink preamble signal.
Alternate signal is sent and sent, and downlink is made in the same procedure as the uplink.
Switch line from preamble code to PN code for communication
(FIGS. 6, 616, and FIG. 6, 605). By the above operation, the terminal device 100,
Since the bidirectional line between the switching devices 200 has been set up,
The switching device 200 sends a dial tone to the calling terminal device.
It is sent out (617 in FIG. 6), and dial monitoring is started. this
Subsequent operation of the exchange device is similar to that of a known exchange device.
To be done. Communication after line setting is as described in Fig. 5.
For call and high speed data, B channel is used for control signal
And low speed data is performed using the D channel. The operation after the transmission of the dial tone is shown in FIGS.
A brief description will be given by using. The central control unit 240 is No.
The spreading code of the spreading modulator 211 of the 1 modulator / demodulator 210 is
PN generated when switching from Limble code to PN code
From the device 213 through the signal receiving / distributing device 230
, A dial tone transmission circuit (not shown) and No. 1 modem
210 and, for example, the transmission highway 261 and the switch
Empty through the network 250 and receiving highway 260
Select a time slot and connect. Switchon here
The network 250 is a time switch and space switch.
J, or a combination of both
Is also good. When the above connection is made, the central control unit 2
No. 40 through the signal receiving / distributing device 230. 1 reversion
Time in the buffer memory 215 of the adjusting device 210
Reception highway 26 selected for slot memory 215-2
Store time slots on 0. After that time
In the slot, time slot switch 215-1
Closed and the 8-bit coded dial tone shift register 21
Received at 5-3. To the shift register 215-3
The 8-bit information entered is immediately transferred to another shift record.
Transferred to the register 215-4 and the shift register 215-
3 is for receiving the signal of the relevant time slot of the next frame
Prepare 8 transferred to the shift register 215-4
The bit information is followed by a total of 2 bits of data and control bits.
Are added under the control of the central controller 240 (see FIG. 1).
The hatched portion of the shift register 215-4), FIG.
As shown in (a), the spread modulator 2 is operated at a speed of 80 kb / s.
Downlink P sent to # 11 and given to the # m1 terminal device
Spread spectrum modulation with N code
It is amplified and transmitted from the antenna 500. # M1 terminal device 100
As shown in FIG.
Then, it is input to the spread demodulator 112. In the spreading demodulator 112, its own terminal device (#m
Demodulate with the downlink PN code of 1) and control the control device 140.
Therefore, through the interface circuit 150, the B channel
Only the signal is taken out, and the PCM demodulator 162 has a predetermined speed.
Converted to and sent out. 800 in the PCM demodulator 162
8-bit code sent at a rate of 0 samples / second
Converts to an analog signal and operates the handset 164 with specified power
Let the caller hear the dial tone. The caller uses the dial 165 to connect to the destination.
Dialing the number
-Detecting this via the interface circuit 150, the interface
5 to the spread modulator 111 via the circuit 150.
Input a predetermined code at the position of the channel and enter the upstream PN code
Spread spectrum modulation is performed by the
It is transmitted from NA 130. On the side of the exchange, this radio signal is transmitted as shown in FIG.
After being received by the antenna 500 and amplified by the transceiver 220
The signal is demodulated by the spread demodulator 212 and the signal is transferred to the shift register 2
It is sent to 16-4. Control signals are hatched in the figure
Since it is input to the part, this part is received by the signal receiving / distributing device 2
It is read by the central controller 240 via 30. When the predetermined dial is received, the central control unit
The device 240 identifies the called terminal device and performs a calling operation.
A free channel with the calling terminal device, that is, the calling terminal
Free time slots on both the transmitting and receiving highways on the device side
Available on both the sending and receiving highways of
Select a time slot and pass through the signal reception / distribution device 230.
Then, the time slot memo of the calling and called terminal device 210
To the 215-2 and 216-2, the selected time slot
Write the security number. On the other hand, switching network
Controlling 250, calling side time slot and called side time
Connect the slots. 2. a. 2 Receiving operation Next, the calling operation of the called terminal device will be described with reference to FIGS.
This will be described with reference to the flowchart of No. 7. In Figure 1, the central system
When the device 240 receives a dial (called number) (see
7, 711), identifying which terminal device the number belongs to
It Now, assume that the called terminal device is #mi in FIG.
Then, the central controller 240 calls the called terminal device #mi.
Available modulator / demodulator, for example, No. 1 in FIG. n change
The controller 210 is selected and captured (FIG. 7, 712). Subsequently, the central control unit 240 makes the called terminal device
Uplink and downlink prea
The signal receiving and distributing device 23
0 through No. 0. PN generator 2 of n modulator / demodulator 210
13 (FIG. 7, 713). Spread by this
The modulator 211 starts transmitting the preamble signal (see FIG. 7,
714), the spreading demodulator 212 is from the #mi terminal device.
Prepare to receive the preamble signal. Preamble signal
Is transmitted through the transceiver 220 and the antenna 500,
# In the mi terminal device 100, the antenna 130 of FIG.
Received and input to the spread demodulator through the transceiver 120.
It As explained in the case of making a call, the terminal device is in an idle state.
Then, the spread demodulator 112 should be pre-loaded so that it can always acquire synchronization.
Since it operates with amble code, the preamble signal is
When it is input, the synchronization capture is controlled by the synchronization circuit 114.
(FIG. 7, 701). When the downlink preamble signal is synchronously captured,
Immediately under the control of the controller 140, the upstream preamble
From the spread modulator 111 to the transmitter / receiver 120,
It is transmitted through the router 130 (702 in FIG. 7). This up
The preamble signal is transmitted from the antenna 500 of FIG.
It is input to the spread demodulator 212 through 220. No.
The spreading demodulator 212 of the n-modulator / demodulator 210 is as described above.
Already received the preamble signal from the #mi terminal device.
The preamble is input because it is set to trust
The signal is immediately acquired (FIG. 7, 715). Synchronous capture
Upon completion of capture, the spread modulator 211 changes the #mi terminal device 1
The preamble code for communication is synchronized with 00.
Switch to the PN code (FIG. 7, 716). Terminal device 100
However, in response to this, the code of the spread demodulator 112 is
Switch from amble code to PN code for communication (Fig. 7, 7
03), and then the spreading code of the spreading modulator 111
Switch from the mumble code to the PN code for communication (Figs. 7 and 7).
04). On the exchange side, No. Expansion of n modulator / demodulator
The spreading code of the dispersion demodulator 212 is synchronized with the terminal device side.
While switching from preamble code to PN code for communication
(FIGS. 7 and 717), No. n modulator / demodulator 210 and #mi
Setting of both uplink and downlink radio channels between the terminal devices 100
Is completed. As described above, the preamble signal
Synchronized acquisition and switching to communication PN code
Since it is performed by the formula, the code switching of FIGS.
Therefore, the central controller 240 has both downlink and uplink channels.
You can confirm that the setup is complete. After that, the central controller 2
40 is called by the calling party as in a normal switching device.
Send a sound and control the called party to send a ringing signal.
(FIG. 7, 718). When sending the call signal
Sends a call signal under the control of the central controller 240.
Put the command to control the terminal on the D channel in FIG.
To the device, and in the terminal device 100, the control device 140
Upon receiving this, the ringer-166 is driven. As described above, at the time of making or receiving a call
In addition, the idle modulator / demodulator 210 is used to communicate with the terminal device 100.
Between the switching devices 200 by means of spread spectrum communication
By setting the channel, the number of simultaneous calls / communication
n wireless communication system can be realized. In this way
The equipment on the switching equipment side has a range of n simultaneous calls / communication.
Within that, it becomes relatively independent of the number of terminal devices, so
Economical in application areas with low call volumes per terminal
is there. In the above embodiment, the terminal device shown in FIG.
The units # m1 and #mi connect the child exchange device 200 on the floor.
The case of making a telephone call through has been described, but the main exchange 3
For example, the # 1 and #l terminal devices make a call / communication via 00.
The same is true for the case of # m1 terminal device and #nj terminal.
End device talks / passes through #m and #n child switching devices
Even if you receive a message, the exchange operation of the exchange device is slightly different.
Therefore, the wireless channel between the terminal device and the modulation / demodulation device in the switching device is
Parts related to the present invention, such as channel setting, call detection, and calling
The same is true for minutes. Therefore, the exchange method is a decentralized system.
Control, centralized control, or configuration of time-division call paths
The present invention can be applied without being affected by the above. Method of transmitting signal between switching device and terminal device
Is also limited to the format shown in FIG.
Alternatively, B + B + D shown in FIG.
There is no problem even if the method is different. Furthermore, in the example
For telephone calls, dial 165
Then, the speaker calls the Tonlinger 166 to transmit and receive.
I explained the case of talking on the device 163,164,
After the call path is set, the spread modulator / demodulator 11 in the terminal device 100
1, 112 and the connection of the PCM modulator / demodulators 161, 162,
Switch to the data terminal device 170 and perform data communication.
Is also possible, and instead of the dial 165, a data terminal
Enter the other party's number / code using the keyboard in the device 170
It goes without saying that it is also possible to force connection
There is no. In this embodiment, one time slot is targeted for a telephone.
8 bit, 8000 frames / sec.
As mentioned above, the digital radio channel is
Since the channel is set to 1 channel, the switching device
Switch device or even sending an image signal
There is no. 2. b Second Embodiment A second embodiment is a system in which a switching device is used as shown in FIG.
Spreading sync signal by RAM spread signal 2
80 to transmit spectrum to the switching equipment and terminal equipment.
Operate in sync with each other through a distributed communication channel
This enables the spread spectrum modulation / demodulation equipment on the switching equipment side.
This makes it possible to use the time division multiplexing of the device 210. The exchanges 200 and 300 have a first realization.
Similar to the example, it is composed of 8000 frames per second,
Eway 260-1 to 260-r and 261-1 to 26-2
On 61-r, one frame consists of n time slots.
Shall consist of These frames, time slots, etc.
Is the synchronization supplied from the synchronization signal generation circuit 270 of FIG.
The signals are synchronized. Each terminal device 100 has a separate spectrum
PN code for ram spreading, PNU (for upstream) and PND
(For downhill) is given. Terminal device J (not shown in FIG. 4)
The PN code for (abbreviated) is represented as PNUj and PNDj.
You In the present embodiment, further, all the devices operating with the same synchronization signal are
The PN code PNC for receiving the synchronization signal, which is common to the terminal devices,
It is provided. This PNC also plays the role of the preamble code.
Add A switching device, eg, 200, enters operation.
And the spread sync signal generation circuit 280 of FIG.
In response to the synchronization signal from the circuit 270, the terminal device synchronization signal
The spectrum is spread by the spread code PNC, and the transmitter / receiver 22
0, transmit through antenna 500. Spread transmitted
FIG. 8 shows the synchronization signal. FIG. 8 (a) shows the extension transmitted from the exchange.
The sync signal is shown on the time axis, below the horizontal axis in the figure.
In the PNC, the signals SNC1 to SNCn on the upper side of the horizontal axis are expanded.
It indicates that the spread modulation is performed by the scattered code PNC. Synchronization
No. SNC1 to SNCn correspond to time slots.
By receiving this, the receiving side can
You can identify the security number. That is, it also becomes a frame sync signal.
ing. Here, this synchronization signal is a preamble signal.
Since it also doubles as a function, in order to shorten the time until synchronization acquisition
The spread code PNC is a simple code and
Since it is required to repeat the signal, the spreading code P
The length of NC is the time slot length or its integer
It is preferably 1. 2. b. 1 Terminal device start-up operation On the terminal device side, power is turned on and
Of the switching device 200/300
It waits for incoming calls or makes outgoing calls in synchronization with.
This state is set by the flow chart of FIGS. 3, 8 and 9.
explain. In FIG. 8, the terminal device J is turned on and off.
Since it is performed independently of the operation of the switching device, it is initially synchronized.
It is not removed. When the terminal device J is powered on (Fig.
8 (b)), the control device 140 of FIG.
The operation is started under the control of the device 140 (FIG. 9, 90).
1). First, the PN generator 113 is used for receiving the spread sync signal.
PN code PNC is generated (902 in FIG. 9), and spread demodulator
112 starts the demodulation operation with the PN code PNC (Fig.
9, 903). On the other hand, the synchronization circuit 114 includes the PN generator 1
13 to start the synchronization acquisition operation (FIG. 9, 91).
1). When the power is turned on, as shown in FIG.
The PN code of the spread demodulator 112 is not synchronized
No output is obtained from the spread demodulator 112, but the synchronization circuit
If the received signal is synchronized with the control of 114, the spread demodulator
The output is obtained from 112 (904 in FIG. 9), and the synchronization acquisition is performed.
Completed (FIG. 9, 912), the synchronization circuit 114 starts the synchronization acquisition operation.
The work shifts to the synchronous tracking operation (913 in FIG. 9). By completing the synchronization acquisition, reception synchronization
The switch's time slot number is derived from the signal
By this, the clock and time in the terminal device 100
Matching synchronization signals such as slots and frames to the switching equipment
It After that, as shown in FIG. 8 (b), the data is received approximately every frame.
The synchronization error is corrected by the received synchronization signal. The controller 140 confirms that the synchronization acquisition is completed.
And controls the PN generator 113 to control the spread demodulator 11
The PN code to 2 is given from the PNC to the local terminal device.
Switching to the PN code PNDj (905 in FIG. 9), diffusion recovery
The modulator 112 starts the demodulation operation with the PN code and PNDj.
(FIG. 9, 906). At this time, in the terminal device 100,
What time slot does the 200/300 call in?
I do not know, so as shown in Figure 8 (b)
The demodulation operation is performed by PNDj. In sync
Therefore, for example, as shown in Fig. 8 (b), n + 1 time slot
The spread demodulator 11 is controlled by controlling the PN generator 113 for each
The PN code of 2 is changed to PNC and the synchronization signal is received. The controller 140 outputs the output of the spread demodulator 112.
The next time slot if no signal is detected.
Signal continues to be detected (Fig. 9, 907)
If there is an incoming call using the timeslot,
That is, the operation of the spread demodulator 112 is performed
It is fixed to the slot, and other times are set to prevent malfunction.
The demodulation operation in the slot is stopped (908 in FIG. 9). Na
For receiving the synchronization signal, for example, in order to simplify the control,
As described above, the time slot immediately before the relevant time slot is
Fixed in place. Of the above operations, the determination of FIG.
When the terminal device is idle,
Is the operation. 2. b. 2 Calling operation Next, the operation when the terminal device makes a call is shown in FIGS.
And the time relationship diagram of FIG. 10 and the flowchart of FIG.
Use to explain. The caller lifts the handset of terminal device J
Then, the hook switch (not shown) is closed.
Is detected by the control device 140 of FIG.
From the PN generator 113 via the interface circuit 150.
To generate a PN code (PNUj), and the spread modulator 111
To call the PN using all time slots
The transmitter / receiver 120 and the antenna 13 are spread-modulated with a code.
It transmits through 0 (1102 in FIG. 11). Where the expansion
The signal to be dispersedly modulated is, for example, B + D, as shown in FIG.
Alternatively, a signal having a configuration such as B + B + D, where B
The description will be made assuming the + D format. That is, in FIG.
TS1, TS2, etc. at the top of the horizontal axis indicate time slot numbers.
I, the hatched part is the D signal, the part without hatching
Represents the B signal. 10 (a), (b), (e),
In (f), each frame does not start from TS1.
The reason is that it is based on the highway of the switching equipment.
is there. The calling signal is a signal of a specific pattern or
Sends the caller and calling conditions (telephone, data, etc.)
And depends on the system. Also, in terms of time
Is the exchange device shown in FIGS. 8 (b) and 10 (f).
Based on the synchronization signal SNC sent from
And synchronize and send. In the exchange apparatus 200/300, FIG.
The central control unit 240 of each modulator / demodulator 210 (same server
When multiple modulation / demodulation equipment is installed in the screw area
Free time, for at least one of them)
Uplink PN signals (P
NU ~) drives the sequential spread demodulator 212 and all available terminals
The device is scanned for outgoing calls (Figs. 11 and 11).
11). Now, FIG. 10B will be described. Correspondence
If the modem 210 on the side of the switching device that operates is No. 1 device
Then, the central controller 240 makes the time slot of the frame q
Call detection of terminal device m on To 1 (on highway)
Therefore, No. The terminal device is connected to the PN generator 213 of one device.
m upstream PN code PNUm is generated, and the spread demodulator 21
2 was activated, but no signal was received and no call was detected
Indicates that it was true. Continued time slot 2 (highway
The above) is already used for communication with the terminal device i. Time slot 3 of frame q (highway
B)), because the calling of terminal device J is detected,
With the same control as in the case of
The spread demodulator 212 is driven (FIGS. 11 and 1112). end
In the end device J, as shown in FIG.
Signal is spread-modulated with PN code PNUj and transmitted.
Then, the calling signal is demodulated by the spread demodulator 212 and controlled.
It is detected by the device 217. And the signal receiving / distributing device 23
The central controller 240 is notified via 0 (FIGS. 11 and 1).
113). The central controller 240 has a spread demodulator 212
Since the calling signal is detected by the PN code PNUj, the terminal
It is identified that the device J makes a call (FIG. 11, 111
4). The central controller 240 uses the dial tone connection (transmit
Sending sound, connecting to push button signal receiver, etc.)
For upstream (highway transmission) time slots and downstream
(Highway reception) Select a time slot. this
When the up time slot is the time used for
Slots or different time slots can be used (Fig. 1
1, 1115). Then select the down time slot you selected.
For example, TSn (time slot on highway
No. 1). 1 modulator / demodulator 210 spread modulator
Receive signal to operate 211 with PN code PNDj
When the control device 217 is instructed via the distribution device 230,
In addition, the uplink time slot is, for example, TS2 (highway
Instruct the terminal device J to allocate the above time slot 3)
To show. The controller 217 controls the PN generator 213.
Then, the spread modulator 211 outputs the time slot TSn.
It operates with the PN code PNDj and the spread demodulator 212
Operates with PN code PNUj in slot TS2
(Fig. 11, 1116). Buffer memo at the same time
The upstream time slot number TS2 via
Input to the spread modulator 211 as a signal and send to the terminal device J.
(Fig. 10 (e), Fig. 11, 1117). At this point, the modulator / demodulator 210 and
It is not necessary to connect the ways 260 to / 261. Well
In addition, the uplink time slot uses the time
In a system that changes from lot to lot,
After sending the slot number to the terminal device,
The time on the exchange side is synchronized with the controller 111.
It is preferable to switch lots. 2 synchronous times
Path 214 provides synchronization tracking for spreading demodulator 212. In the terminal device J, as shown in FIG.
As shown in FIG. 10 (f), the spread demodulator 112 (FIG. 3)
Operate with PN code PNDj in all time slots
Therefore, in the time slot TSn, the uplink time
Lot number TS2 is received (Fig. 11, 1103) and exchanged
Originating call detection has been performed in the device 200/300.
Is confirmed, the control device 140 controls the PN generator 113.
Control the spread modulator 111 operation to TS2.
Furthermore, the operation of the spread demodulator 112 is fixed to TSn (see FIG. 1).
0 (a), (f), FIGS. 11, 1104). Reception of synchronization signal in terminal device 100
No matter which time slot the call arrives at,
N + 1 time slot for signal detection with frame delay
It is assumed that the data will be received for each eye (Fig. 8 (b)), but for communication
After the time slot is fixed, the
Imslot is also fixed. This is an n + 1 time slot
If you continue to receive the synchronization signal for each eye, communication will occur once every n frames.
For receiving the synchronization signal in the time slot for
Thus, in the example of FIG.
The sync signal is being received in the time slot. On the side of the exchange, the terminal device 100 goes up
After sending the imslot number, (from terminal device 100
A signal confirming that the upstream timeslot number has been received
May be sent, and after receiving this), for example, press
A button signal receiver (not shown) is selected and captured, and the calling end is already
With the time slot on the highway that is selected for
Set up the channel between
The imslot number indicates the buffer memory of FIG.
And 216 are operated, and No. 1 modulator / demodulator 210 and
Eway 260-1 and 261-1 are connected (Fig. 1
1, 1118). A tone is sent from the push button signal receiver.
If you dial on the terminal device,
The frequency signal is sent to the pushbutton signal receiver. The multi-frequency signal in the terminal device 100 is
Although detailed description of the signal sending operation is omitted, the control device 140
PCM coded, which corresponds to the dial signal received by
Sequentially inputting the multi-frequency signal to the spread modulator 111.
Done by With the above operation, the terminal device 100 and the exchange device
Since the wireless channel between 200/300 has been set,
The operation of the subsequent switching device 200/300 is the same as that of the known one.
Is performed. In the above description, for example, in FIG.
Send the upstream time slot number from the exchange to the terminal
In the case, it is written that it is sent in one frame, but D channel
Even if you send it over multiple frames using
It is clear that there is no obstacle, and it is not limited to the figure
There is no. Although the description is omitted, the addition of the D channel, etc. is performed by referring to FIG.
In the same manner as in the first embodiment shown in FIG.
15 and 216. 2. b. 3 Incoming call operation Time relationship diagram of FIG. 2, FIG. 3 and FIG. 12 and of FIG.
The operation for an incoming call will be described with reference to a flowchart.
In FIG. 2, the central controller 240 receives the called number.
Then (FIG. 13, 1311), the called number is immediately changed to the called end.
It is identified that the end device is, for example, “J” (FIG. 13,
1312). Subsequently, the central controller 240 determines that the called terminal device is
Select a modulator / demodulator 210 capable of calling the device J.
It Only one modulation / demodulation device 210 that can call the terminal device J
In the case of
Modulation / demodulation with empty channel between call terminal or incoming line
A device is selected (FIGS. 13 and 1313). In parallel with this, the calling terminal device or the
The modulation / demodulation device 210 selected as the line, for example, No. n device
Both highways for sending and receiving empty time slots between
Select on 260-r, 261-r. This embodiment
Now, the highway time slots and radio channel
No. n modulation / demodulation equipment
Both up and down times between the device 210 and the called terminal J
This means that the slot has been selected (FIGS. 13 and 1314).
Here, TSn is the upstream time slot, and the downstream time is
It is assumed that TS2 is selected as the slot (FIG. 12). As described above, the modulator / demodulator 210 and the terminal device are
No. 100, the upstream and downstream time slots are No.
n, No. J, TSn, TS2 have been decided, so central system
The control device 240 receives N signals via the signal receiving / distributing device 230.
o. Gives an instruction to the control device 217 of the n modulator / demodulator 210.
The spread modulator 211 is controlled by the control of the controller 217.
Spreading variation with PN code PNDj in Imslot TS2
Keying operation (Figs. 13 and 1315) and spread demodulation
The device 212 uses the PN code PN in the time slot TSn.
Uj performs spread demodulation operation (FIGS. 13 and 1316),
Set. Further, the control unit 217 determines that the time slot
An incoming signal is input to the downlink buffer memory 215 in TS2.
Required information and upstream time slot number to be used
No. TSn is input, and the spread modulator 211 expands it with PNDj.
Transmit and receive through transmitter / receiver 220 and antenna 500
(FIG. 12 (b), FIG. 13, 1317). No. In the J terminal device 100,
The tena 130 receives this signal and the transceiver 120 amplifies it.
Then, it is input to the spread modulator 112. No. J terminal device 1
00, as shown in FIG.
12 is a PN code PNDj in all time slots,
Since the spread demodulation operation is being performed,
The input signal is immediately demodulated, and the incoming signal
The slot number TSn is detected as a signal (FIG. 12).
(C), FIG. 13, 1301). In the terminal device 100, the control device 140 is
This is received through the interface circuit 150 and the incoming call processing is performed.
And the spread demodulation by controlling the PN generator 113.
The operation of the instrument 112 is fixed to the time slot TS2,
On the other hand, fix the reception of the sync signal to the previous time slot.
It That is, PN code PNC at the position of time slot TS1
The demodulation operation is performed by and the synchronization signal SNC2 is received (Fig. 1
2 (c), FIGS. 13, 1303). Similarly, the spread modulator 111 also receives a signal.
P to operate in the received time slot TSn
Control the N generator 113 (FIG. 12 (d), FIG. 13, 1)
302). The control device 140 receives the call from the spread modulator 111.
Enter a confirmation signal to confirm that the
Switching device 200 /
It is sent to 300 (FIG. 13, 1304). By the above operation, the switching device 200/3
The channel between 00 and the terminal device 100 has been set
Then, the control device 140 passes through the interface circuit 150.
Then, ringer 166 is sounded and a calling signal is transmitted.
(FIG. 13, 1305). On the other hand, on the switching device side, the No. n change
The spread demodulator 212 of the demodulator 210 uses a time slot
Since it operates with PN code PNUj in TSn,
The confirmation signal sent from the terminal device 100 is immediately restored.
Adjusted (FIGS. 13 and 1318) and signaled from controller 217.
It is transferred to the central control unit 240 via the reception distribution unit 230.
Be done. The central control unit 240 is a channel with the terminal device.
Now that we have confirmed the settings, we can perform incoming connection processing such as sending ringing tone.
Perform (FIG. 13, 1319). As described above, the present invention
According to this, it is possible to make wireless between the switching device and the terminal device.
Will be possible. Incidentally, refer to the states of (b) and (e) of FIG.
Explaining for consideration, first, (b) shows the time slot T
Sn is terminal device K, time slot TS1 is terminal device
It is used for I and time slot TS2 is frame q
Indicates that the terminal device J has started to be used. FIG. 12E shows the time slot of frame q.
The terminal device M of the terminal TSn (TS1 on the highway)
Call detection was performed, but the call was not detected.
And time slot T from frame q + 1
Sn indicates that the terminal device J has been used. Obey
For subsequent call detection, use another empty time slot.
Will be done. Also, the time slot TS1 is
The terminal device K uses the time slot TS2 for the terminal device I.
Has been used. The second embodiment will be briefly described above.
However, after the wireless line has been set up, the time
Same as digital exchange system with slot memory
It is clear that the same operation is performed, and known communication systems
All the functions of can be introduced. In the present embodiment, the highway of the exchange is used.
As it is, it is extended to the wireless channel between the switching device and the terminal device.
However, the buffer memory 215 of FIG.
216 has a time switch function, that is, a time slot
With the function of switching, the time
Lot allocation is completely independent of the exchange highway
And the number of time slots, ie transmission
The speed can also be independent. For example,
The time slots of the flannel are rigged to each terminal device.
The highway from the buffer memories 215 and 216
A configuration such as concentrating at the point where the connection is made becomes possible. The second embodiment, as shown in FIG.
Both the main switching device and the child switching device have a switching function.
In other words, the connection between the terminal devices accommodated in the same child exchange device
The following is a case where the processing is performed in the child exchange device.
The buffer memories 215 and 216 have time switch
Highways 260-1 to 260-r, 2
61-1 to 261-r are cables 600 (for example, optical fiber).
High-speed digital highway by IBA)
Instead, the central control unit 240 provided in the main switching unit
Communication with the control device 217 in the modulator / demodulator 210 is high.
Some of the time slots on the way are used as signaling channels
If configured to be used, the child exchange apparatus of FIG.
The position 210 itself will improve. At this time, the same
All communication between terminal devices in the modulator / demodulator is also a node device
610, via cable 600, via main switching device 300
Will be held in. In other words, the modulation / demodulation device 21
Configure a switching system that uses 0 as a remote concentrator
It is also possible. The above embodiment is based on the voice of 64 kb / s.
I explained ISDN as a standard.
If the slot is made larger, the message slot method
It can also be used for packet communication. Further, the exchange system of the present invention is a terminal device.
The access channel from the
Since it has it, it has a star-shaped wiring in terms of function.
Equivalent to that of the contention control switching device
In other words, if the terminal device sends a calling signal,
Start communication by receiving the communication start permission signal from the
For example, if you send packets, the star-shaped local area
It can realize the same function as a network (LAN). One of the characteristics of spread spectrum modulation
If you take advantage of noise resistance, the amount of attenuation will be large in the high frequency range.
Wired transmission using existing local cable for voice communication
It is also possible, as a subscriber line transmission system in ISDN
Can be utilized. Time division multiplexing as shown in the second embodiment.
In the case of spread spectrum modulation of the converted signal,
As a transmission line between the terminal equipment and the switching equipment, the twisted pair
Oh, or use a wired transmission line such as a coaxial cable,
Also connect multiple terminal devices on the same cable.
If the connection type or multi-drop type
A single cable can be used for multiple terminal devices without the use of magnetic waves.
It also makes it possible to provide communication between the switching and switching devices. This method is used along the railway, along the road, or
Uses a cable installed along the power line to communicate
In such a case, one cable can be used for multiple terminals that are independent of each other.
It is very economical because it can provide the communication path of. According to the present invention, confidentiality and noise resistance are high.
Telephone exchange that uses a digital exchange system
Providing a wireless telephone exchange system with good compatibility with the system
can do. This also allows you to
In case of relocation or moving of terminal equipment, no wiring work is required.
Since there is no need to
System can be built. Especially in office applications
Can also use weak radio waves, so there are problems with radio wave management.
It has the effect of making the system wireless.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram on the exchange side showing a first embodiment of the present invention. FIG. 2 is a system configuration diagram of an exchange device side showing a second embodiment of the present invention. FIG. 3 is a system configuration diagram showing an embodiment of the terminal device side according to the present invention. FIG. 4 is a configuration diagram of a distributed switching system showing an example of a switching system according to the present invention. FIG. 5 is a time relationship diagram showing a relationship between a signal on a highway and a signal on a wireless transmission path to a terminal device according to the first embodiment of the present invention. FIG. 6 is a flowchart showing a calling operation according to the first embodiment of this invention. FIG. 7 is a flowchart showing an incoming call operation according to the first embodiment of this invention. FIG. 8 is a time relationship diagram showing the states of the synchronization signal and the signal of the demodulation operation from the power-on of the terminal device to the standby for synchronous acquisition and reception in the second embodiment of the present invention. FIG. 9 is a flowchart showing an operation from power-on to standby for incoming call of the terminal device according to the second embodiment of the present invention. FIG. 10 is a time relation diagram showing a relation of signals during a calling operation according to the second embodiment of the present invention. FIG. 11 is a flowchart showing a calling operation according to the second embodiment of the present invention. FIG. 12 is a time relation diagram showing a relation of signals during an incoming call operation according to the second embodiment of the present invention. FIG. 13 is a flowchart showing an incoming call operation according to the second embodiment of the present invention. [Description of Codes] 100 ... Terminal Device, 111 ... Spread Modulator, 112
... Spreading demodulator, 113 ... PN generator, 114 ... Synchronous circuit, 120 ... Transceiver, 130 ... Antenna, 1
40 ... Control device, 150 ... Interface circuit,
161 ... PCM modulator, 162 ... PCM demodulator, 163
… Speaker, 164… Receiver, 165… Dial,
166 ... Ringer, 170 ... Data terminal device, 20
0 ... Switching device, 210 ... Modulation / demodulation device, 211 ... Spreading modulator, 212 ... Spreading demodulator, 213 ... PN generator, 214 ... Synchronous circuit, 215, 216 ... Buffer memory, 217 ... Control device, 220 ... Transceiver, 230 ... Signal receiving / distributing device, 240 ... Central control device, 250 ... Switching network, 300 ... Switching device, 400 ... External cable, 500 ... Antenna, 600 ... Cable, 610 ... Node device.

Claims (1)

[Claims] 1. In a wireless switching system having a plurality of wireless terminal devices and a switching device for switching and connecting a call from the wireless terminal devices, each of the plurality of wireless terminal devices includes a transmitter and a transmitter. A first modulator for digitally modulating the analog voice signal, a first demodulator for demodulating the digitally modulated voice signal into an analog voice signal, and an analog voice signal from the first demodulator are output. A receiver and a first radio transmitter / receiver for transmitting the digitally modulated voice signal from the first modulator to the switching device and transmitting the digitally modulated voice signal from the switching device to the first demodulator. And a transmission highway in which a plurality of time slots accommodating digitized voice signals are multiplexed, and the transmission highway. Switch means for switching and connecting a call from the wireless terminal device by controlling a time slot of the reception highway, and interface means connected to the transmission highway and the reception highway, and a digital signal in a predetermined time slot of the transmission highway. Extraction means for extracting an audio signal, a second modulator for digitally modulating the signal from the extraction means, and second demodulation for demodulating the digitally modulated audio signals from the plurality of wireless terminal devices into a digital audio signal. Interface and a sending means for sending the demodulated digital voice signal into a predetermined time slot of the receiving highway, and a digital radio signal is transmitted and received between the interface means and the wireless terminal device. A second transceiver which is A second transceiver for transmitting a digitally modulated voice signal to the wireless terminal device and transmitting a digitally modulated voice signal from the wireless terminal device to the interface means, and a transmission highway and a reception highway of the exchange device. And a control means for controlling the switch means and the interface means, and the incoming and outgoing calls from the plurality of wireless terminal devices are accommodated and exchanged in a predetermined time slot. 2. In the wireless telephone switching system, the switching device includes a plurality of sub-switching devices including the interface means and a second transceiver, and the plurality of sub-switching devices and the switch means include the transmitting highway and the receiving highway. 2. The wireless telephone exchange system according to claim 1, wherein the exchange system is a switching device connected by. 3. In the wireless telephone exchange system, the plurality of wireless terminal devices, a plurality of switching devices according to claim 1 or 2 and at least one switching device according to claim 1 or 2 are provided from the wireless terminal device. And a first switching device having a central line interface for connecting incoming and outgoing calls to a wireless telephone switching system and another communication system, wherein the plurality of switching devices are connected to the first switching device by the transmission highway and the reception highway. Alternatively, the wireless telephone switching system according to claim 1 or 2, which is a system including a distributed switching device connected by another transmission highway and another reception highway.