JPH0595577A - Time sharing communication method for private communication network - Google Patents

Abstract

PURPOSE:To enable communication between plural private communication networks PN1 and PN2 using TCM signals time-compressed and partitioned into the time slots of frame constitution without interposing a telephone network for public communication. CONSTITUTION:An interface IF is provided between a radio base station 30 and the private communication network PN1/PN2 equipped with a movable radio equipment 100 and a cable telephone set 200. The time slot as the TCM signal from the PN1 is turned to a non-TCM, source signals are restored, turned to the TCM corresponding to the standard of the private communication network PN2, and the time slot is transmitted to the side of the PN2. The signals from PN2 to PN1 are similarly processed as well. Therefore, since it is not necessary to detour a telephone network 10, transmission quality is not degraded, transmission delay time is shortened and the burden of charging the telephone network 10 is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection between local communication networks in an era when a large number of local communication networks are used.
Specifically, one private communication network has a large number of wired terminal means and mobile wireless terminals, and a telephone signal used for communication between a mobile wireless terminal or a wired terminal and another mobile wireless terminal or a wired terminal. For example, time division time compression multiplexing (a format in which a time-compressed partitioned signal is time division multiplexed into time slots having a frame structure, hereinafter referred to as T
(Abbreviated as CM) signal, and when the same TCM signal as above is used in other local area communication networks,
The present invention relates to a communication method that enables mutual connection of these two local communication networks.

[0002]

2. Description of the Related Art In mobile communication using voice to which a small zone method is applied, a method using a time division time compression multiplexed signal is described in the following document.

Reference 1. Ito "Study on mobile phone systems-Proposal of time division time compression FM modulation system-" IEICE Technical Report RC
S89-11 July 1989

Reference 2. Ito "Study on mobile phone system-Theoretical study on time-division time-compression FM modulation system"
RCS89-39 October 1989

Reference 3. Ito "Examining mobile phone methods-
A Study on Multipath Propagation Characteristics of Time Division Time Compression Multiplex FM System- "IEICE Technical Report RCS89-47 January 1990

Reference 4. Ito "Elucidation of multiple load gain of time division time compression multiplex telephone signal and its application to FM mobile communication" IEICE Technical Report RCS89-65 Mar. 1990.

That is, in Reference 1, a transmission signal (baseband signal) is divided into predetermined time interval units and stored in a memory circuit, and when reading this, the speed is n times faster than the speed of storing in the memory circuit. Built in mobile radios and radio base stations to read at a predetermined time slot, angle-modulate or amplitude-modulate a carrier wave with the signal accommodated in this time slot, and to transmit and receive intermittently in time. , A switch for a radio receiving circuit having a receiving mixer that communicates with each other, a radio transmitting circuit having a transmitting mixer, a synthesizer applied to the receiving mixer of the radio receiving circuit, and a synthesizer applying to the transmitting mixer of the radio transmitting circuit A circuit is provided, and the output of the synthesizer applied to each is interrupted, and this interrupted state is transmitted and received. For the wireless base station that communicates with each other in an expected manner, the same method as described above for synchronizing the intermittent transmission and reception with that of the mobile wireless device is used, and the receiving side extracts only the signal accommodated in the predetermined time slot. Therefore, by opening and closing the wireless receiving circuit, receiving and demodulating, the signal obtained is stored in the memory circuit, and at the time of reading this, by reading at a low speed of 1 / n of the speed stored in this memory circuit, A system example in which a system that enables reproduction of a transmitted baseband signal, which is an original signal, is constructed has been reported.

Next, in Document 2, the above-mentioned TCM is used.
(Time-division time compression multiplexing) -Adjacent channel interference and co-channel interference, which are problems when the FM system is applied to a small zone, are being studied, and the system can be realized by selecting system parameters appropriately. The possibility is shown.

Further, in Reference 3, the effect of multipath fading that a TCM signal receives during transmission in space is examined, and guard time is set between time slots as a measure for removing or reducing this effect. I suggest you do.

Further, in Reference 4, the multiplex load gain, which has been known to exist in FDM (frequency division multiplex) signals in the past, has a multiplex load gain similar to the FDM signal in the time division time compression multiplex (TCM) system. Reveal that, and
It explains the quantification and operation examples of the system. Then, by using this multiple load gain to deepen the modulation depth of the FM, the transmission power can be significantly reduced, and it is expected that the mobile wireless device can achieve a significant power saving. Has been reported.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the system construction example shown in FIG. 1, the communication is performed by using the TCM signal in the same system, and when there are a plurality of systems, if they are interconnected, there is the following problem. Generally, the local communication network is connected to a public communication network or the like. Therefore, when the local communication networks applying the TCM signal try to establish mutual connection, it is necessary to do so via the public communication network interface. However, there are the following problems.

First, the point that the signal transmission path becomes a detour. This may be due to deterioration of signal transmission quality or occurrence of transmission delay. Next, there is a problem of billing (usage fee) associated with using the public communication network, which makes it expensive.

If it becomes possible to directly connect from one local communication network to another local communication network without going through the public communication network,
All of the above problems will disappear.

[0014]

SUMMARY OF THE INVENTION The present invention defines the interface conditions needed to interconnect two private networks that apply TCM signals.
That is, when the parameters of the TCM signal used in each of the two local area networks are clear,
The technical problems that occur in the interface are: the difference in the time compression rate of the TCM signal, the difference in the time length of the time piece of the TCM signal, the difference in the number of multiplexed TCM signals, the difference in the frame length of the TCM signal, the difference in the signal format of the TCM signal If any one of the above is different, it is impossible to directly connect the two local communication networks. Therefore, the interfaces come from one network to another network. It is necessary to convert the frame structure of the signal to the frame structure used in the incoming communication network, and the converting means is provided in the interface so as to absorb the difference between.

That is, the TCM from one of the local communication networks
The original signal is restored even if the signal is made non-TCM, and the signal is converted to TCM according to the standard (parameter) of the other local area communication network.

[0016]

As a result, even if the parameters of the TCM signal used in each of the two local communication networks are different, the operation at the destination of the signal from one local communication network to the other local communication network is different from that of the destination. It became possible to connect to each other exactly as each operation peculiar to the premises communication network.

In the above-mentioned two local communication networks, the transmission path serving as a detour for signals is eliminated because the mutual communication can be directly performed without passing through the public communication network. This is effective in avoiding the possibility of deterioration of signal transmission quality and transmission delay. Next, the problem of billing (usage fee) associated with the use of the public communication network is solved and the communication cost can be reduced.

[0018]

Embodiments of the present invention will be described in the following order. 1. An embodiment in which the present invention is applied to one wireless system (wireless local area communication network). An embodiment in which the present invention is applied to the connection of two private communication networks

1. Embodiment in which the present invention is applied to one wireless system (wireless local area communication network)

1.1. Principle of TCM Signal First, the principle of the TCM signal, which plays a major role in the present invention, will be described.

Telephone signals (0.3 to 3 kHz) are transmitted, for example, 10
After cutting at msec intervals (this is called a time segment), these signals are stored in a memory circuit and then read out at a high speed of 10 times, for example, they are compressed into 1msec time segments. , A packet-like signal having a signal frequency component of 3 to 30 kHz is obtained. As a result of this signal processing, the remaining 9/10 time resulting from the time compression of 10 times is used for the telephone signal (compressed) of another call (TCM signal). Therefore, when viewed from the transmitting end, 10 different compressed audio signals are transmitted in a time division manner. In the case of wired transmission, the obtained TCM signal is amplified to an appropriate level and then sent out to the transmission line. In the case of a wireless system, a fixed wireless base station transmits a TCM signal to FM (frequency modulation)
Then send it out from the antenna. The receiving unit of the mobile radio that received this radio signal extracts only the specified packet-shaped signal in each frame, amplifies it to an appropriate level, demodulates it with a frequency discriminator, and lowers it to 1/10 When read with, the original signal is restored.

1.2. Embodiment in which the present invention is applied to one wireless system (wireless local area communication network)

FIG. 1 shows a conceptual block diagram when the present invention is applied to two local communication networks PN1 and PN2.
Since the two local communication networks PN1 and PN2 have the same configuration, the local communication network PN1 will be representatively described.

The telephone network 10 which is a general public communication network is connected to a private branch exchange 17-1 generally called PBX, and a radio base station 30-1-1 connected to the private branch exchange 17-1 in the private branch communication network PN1. Through 30-1-i, it is possible to communicate with mobile radios 100-1-1 through 100-1-n. The private branch exchange 17-1 has a wired telephone 200-1.
-1-200-1-p are also connected and can also communicate with the telephone network 10. Further, since the private branch exchange 17-1 has a star-shaped network structure in the private branch network PN1, many mobile wireless devices 100 and many telephones 200 included in the private branch network PN1. Any combination of these can be used for communication.

When the private branch network PN1 side and the private branch network PN2 side communicate with each other, both private branch exchanges 17-1 and 17-
This is done via an interface IF for connecting the two.

In FIG. 2, one radio base station 30 is shown as a representative of the radio system of one private network PN1 to which the TCM signal, which is the main function of the present invention, is applied. The operation principle will be described.

Now, in a system to which the present invention is applied, an analog telephone signal is transmitted by TC in order to explain its principle.
The case of using after converting to M will be described.

In FIG. 2, 10 is a general telephone network, and 17 is a private branch exchange (PBX) for switching and connecting the telephone network 10 and a radio system. Reference numeral 30 is a wireless base station, which has an interface with the private branch exchange 17, a circuit for converting the speed of signals, a circuit for allocating and selecting time slots, a control unit, etc. for setting and releasing a wireless line. In addition, the mobile radio 100 (100-1 to 100-
n) has a wireless transmission / reception circuit for exchanging wireless signals with the wireless communication circuit. Here, between the private branch exchange 17 and the radio base station 30, there are transmission lines for transmitting the communication signals 22-1 to 22-n including the communication signals of the communication channels CH1 to CHn and the control signals. The private branch exchange 17 is connected to the private branch communication network PN2 via an interface IF.

FIG. 3 illustrates the principle of the present invention.
The circuit configuration of the mobile wireless device 100 that communicates with the wireless base station 30 is shown. Received signals such as control signals and call signals received by the antenna unit enter the wireless reception circuit 135 including the reception mixer 136 and the reception unit 137, and the output communication signal is the speed restoration circuit 138 and the control unit 140.
Is input to the clock regenerator 141. The clock regenerator 141 regenerates a clock from the received signal and applies it to the speed restoration circuit 138, the control unit 140, and the timing generator 142.

The speed restoration circuit 138 restores the speed (pitch in the case of an analog signal) of the compressed and delimited communication signal in the received signal and inputs it to the telephone unit 101 and the control unit 140 as a continuous signal. ing.

The communication signal output from the telephone unit 101 is divided by the speed conversion circuit 131 at predetermined time intervals, and the speed (pitch in the case of an analog signal) is increased (compressed) and transmitted. Mixer 133 and transmitter 134
And is applied to the wireless transmission circuit 132 including.

The output of the modulator included in the transmission unit 134 is converted into a predetermined radio frequency in the transmission mixer 133,
The signal is transmitted from the antenna unit and received by the wireless base station 30. In order to transmit a radio signal to the radio base station 30 using the time slot permitted to be used by the mobile radio device 100, the timing information from the timing generator 142 shown in FIG. Must have been obtained.

The timing generator 142 supplies the necessary timing to the transmission / reception interrupt controller 123, the speed conversion circuit 131 and the speed restoration circuit 138 by the clock from the clock regenerator 141 and the control signal from the control unit 140. There is.

The mobile radio 100 further includes synthesizers 121-1 and 121-2 and a changeover switch 122.
-1, 122-2 and changeover switches 122-1 and 122
-2 includes a transmission / reception gating controller 123 and a timing generator 142 that generate signals for switching each of -2, and the synthesizers 121-1 and 121-2, the transmission / reception gating controller 123, and the timing generator 142 are control units. It is controlled by 140. Each synthesizer 121
The reference frequency is supplied to the -1, 121-2 from the reference crystal oscillator 120.

FIG. 4 shows a radio base station 30 for explaining the principle of the present invention. The n-channel communication signals 22-1 to 22-n with the private branch exchange 17 are connected to a signal processing unit 31 that forms an interface on a transmission line.

The communication signals 22-1 to 22-n sent from the private branch exchange 17 are input to the signal processing unit 31 of the radio base station 30. The signal processing unit 31 is provided with an amplifier for compensating for transmission loss, and also performs so-called 2-wire to 4-wire conversion. That is, the input signal and the output signal are mixed and separated, and the input signal from the private branch exchange 17 is sent to the signal speed conversion circuit group 51. The output signal from the signal speed restoration circuit group 38 is transmitted to the private branch exchange 17 in the signal processing unit 31 using the same transmission path as the input signal. The input signal from the private branch exchange 17 is input to the signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and the speed (pitch) conversion is performed at predetermined time intervals. receive. The signal transmitted from the radio base station 30 to the private branch exchange 17 is the radio reception circuit 3
The output of No. 5 is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, speed (pitch) converted, and input to the signal processing unit 31.

The control of the radio receiving circuit 35 or the output of the call signal is input to a signal selection circuit group 39 including signal selection circuits 39-1 to 39-n for selecting a signal for each time slot, and here, each call channel is selected. Call signals are separated corresponding to CH1 to CHn. This output is input to the signal processing unit 31 after being restored in the signal speed (pitch) by the signal speed restoring circuit group 38 including the signal speed restoring circuits 38-1 to 38-n provided for each channel. After receiving the 4-wire / 2-wire conversion, this output is transmitted to the private branch exchange 17 as a communication signal 22-.
1 to 22-n.

Next, the function of the signal speed conversion circuit group 51 will be described. The input signal such as a voice signal or a control signal, which is divided into a certain time length, is stored in a storage circuit, and the speed is changed when reading the input signal, and the read signal is read at a speed of, for example, 15 times that of the storage time. Can be compressed. The principle of the signal speed conversion circuit group 51 is tape
This is the same as playing back the sound recorded by the recorder at high speed. In practice, for example, CCD (Charge Coupl
ed Device) and BBD (Bucket Brigade Device) can be used, and the memory used in a television receiver or a tape recorder for compressing or expanding the time axis of conversation can be used (reference: Kosaka et al. "Tape recorder that compresses / expands the time axis of conversation" Nikkei Electronics July 26, 1976 92-1
33).

CCD exemplified by the signal speed conversion circuit group 51
The circuit using the BBD or BBD can be used as it is for the signal speed restoration circuit group 38 as described in the above document. In this case, the clock from the clock generator 41 and the control signal from the control unit 40 are used. By receiving the timing signal from the timing generator 42 that generates the timing, the read speed is set lower than the write speed.

The control or voice signal output from the private branch exchange 17 via the signal processing unit 31 is input to the signal speed conversion circuit group 51, and after the speed (pitch) conversion processing is performed, the time slot It is applied to a signal allocation circuit 52 which separately allocates signals.

The signal allocating circuit 52 is a buffer memory circuit, which outputs 1 signal output from the signal speed converting circuit group 51.
A high-speed signal corresponding to a delimiter is stored in memory, the signal in the buffer memory is read out by the timing information from the timing generation circuit 42 given by the instruction of the control unit 40, and the signal is sent to the wireless transmission circuit 32. As a result, when the communication signals are viewed as channels, they are arranged in series without overlap in time series, and when all the communication signals or control signals described later are implemented, it is as if they were continuous signal waves. become.

The above signals are sent to the wireless transmission circuit 32. The state of this compressed signal will be described with reference to FIG.

The output signals of the signal speed conversion circuit group 51 are input to the signal allocation circuit 52 and given time slots in a predetermined order. S in FIG. 5 (a)
Dn, SD2, ..., SDn indicate that the speed-converted communication signals are assigned to each time slot. Here, in one time slot, a synchronizing signal and a call signal or / and a control signal are accommodated as shown in the figure. When the call signal is not installed, an empty slot signal is added to the call signal portion only with the synchronization signal, or in some systems, no signal including the carrier wave is transmitted. In this way, as shown in FIG. 5A, in the wireless transmission circuit 32, a signal forming one frame in the time slots SD1 to SDn is added to the modulation circuit. The multiplex signals that are time-series to be transmitted are angle-modulated in the wireless transmission circuit 32, and then transmitted to the space from the antenna section.

Regarding the transmission of the control signal between the radio base station 30 and the mobile radio 100 prior to the call in the incoming and outgoing call of the telephone, whether the telephone signal is in the band or out of the band. It is possible. FIG. 6 shows these frequency relationships. That is, in the figure (a), the out-of-band signal is illustrated, and the low frequency side (250 Hz) or the high frequency side (3850 Hz) can be used. This signal is used, for example, when sending a control signal during a call. FIG. 6B shows an example of the in-band signal, which is used at the time of incoming and outgoing calls. In the above examples, tone signals are used. However, by increasing the number of tone signals or modulating the tones to form subcarrier signals, it is possible to transmit various types of signals at high speed.

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, it is also possible to digitally encode the voice signal and time-division multiplex both of them for transmission. FIG. 7 shows the circuit configuration in this case. FIG. 7 shows an example in which the voice signal is digitized by the digital encoding circuit 91, and the data signal and the data signal are multiplex-converted by the multiplex conversion circuit 92 and applied to the modulation circuit included in the wireless transmission circuit 32. However, for digital data signals, the analog signal multiple load gain, which will be described later, does not normally exist, so this point must be noted in the system design. Then, if the opposite receiver receives the signal and the demodulation circuit performs the reverse operation to that shown in FIG. 7, the audio signal and the control signal can be separately taken out.

On the other hand, the signal sent from the mobile radio 100 is received by the antenna section of the radio base station 30 and input to the radio receiving circuit 35. FIG. 5B schematically shows this upstream input signal. That is, the time slots SU1, SU2, ..., SUn represent transmission signals addressed to the radio base station 30 from the mobile radios 100-1, 100-2, ..., 100-n. Further, when the contents of each time slot SU1, SU2, ..., SUn are shown in detail,
As shown in the lower left of FIG. 5B, it is composed of a call signal and / or a control signal. However, the synchronization signal can be omitted depending on the case where the distance between the mobile wireless device 100 and the wireless base station 30 is small or the signal speed. Further, when the waveform of the radio carrier of the uplink radio signal of FIG. 5B in a time slot is schematically shown, FIG.
It becomes like (c). Similarly, the downlink transmission waveform from the wireless base station 30 to each mobile wireless device 100 in FIG.
As shown in (d).

The control signal of the input signals arriving at the radio base station 30 is immediately added from the radio receiving circuit 35 to the control unit 40. However, depending on the size of the speed conversion rate, it is possible to add the signal from the output of the signal speed restoration circuit group 38 to the control unit 40 after performing the same processing as the call signal. The call signal is applied to the signal selection circuit 39. The signal selection circuit group 39 includes a control unit 4
In response to an instruction from the control signal from 0, a timing signal from a timing generation circuit 42 that generates a predetermined timing is applied, and a synchronization signal, a call signal or a control signal is separately output for each time slot SU1 to SUn.

Each of these signals is sent to the signal speed restoration circuit 38.
Is input to. This circuit has a function of performing the inverse conversion of the speed conversion circuit 131 (FIG. 3) in the mobile radio device 100 on the transmission side, whereby the original signal is faithfully reproduced and transmitted to the private branch exchange 17. Become.

The mode of transmitting the signal space in the present invention will be described below with reference to the required transmission band and the relationship with the adjacent radio channel.

As shown in FIG. 4, the control signal from the control unit 40 is applied to the radio transmission circuit 32 in parallel with the output of the signal allocation circuit 52. However, depending on the size of the speed conversion rate, after the same processing as the call signal is performed, the signal allocation circuit 5
It is also possible to add from the output of 2 to the wireless transmission circuit 32. Next, also in the mobile wireless device 100, as shown in FIG. 3, the circuit configuration required when the communication path is one channel among the functions of the wireless base station 30.

Original signal, eg voice signal (0.3 kHz-
A frequency distribution of 3.0 kHz) on the output side when the signal speed conversion circuit group 51 (FIG. 4) is passed is as shown in FIG. That is, if the audio signal is converted 15 times as described above, the frequency distribution of the signal is as shown in FIG.
It means that the frequency is expanded to 4.5 kHz to 45 kHz. Although the frequency distribution of the signal is expanded here, it should be noted that the shape of the waveform simply undergoes a similarity transformation in which the frequency axis is stretched, and the waveform itself does not change.

Now, FIG. 9 shows a case where the control signal is simultaneously transmitted using the lower frequency band of the audio signal. Of these signals, control signals (0.2 to 4.0)
kHz) and the speech signal CH1 (represented as SD1 at 4.5-45 kHz) are contained in a time slot, for example SD1. The same applies to audio signals accommodated in the other time slots SD2 to SDn.

That is, the time slot SDi (i =
2, 3, ..., N) is a control signal (0.2 to 4.0 kH)
z) and the communication signal CHi (4.5 to 45 kHz). However, the signals in each time slot are arranged in time series, and the signals in a plurality of time slots are not simultaneously applied to the wireless transmission circuit 32.

When these call signals are added to the angle modulator included in the radio transmission circuit 32 together with the control signal, a required transmission band of at least f _C ± 45 kHz is required. However, f _C is a radio carrier frequency. If there are a plurality of wireless channels given to the system, the speedup of signals by the signal speed conversion circuit group 51 is limited to a certain value due to the limitation of these frequency intervals. F is the frequency interval of a plurality of wireless channels
Let _rep be the maximum signal speed f _H due to the speedup of the audio signal described above, and the following inequality must be established between the two. f _rep > 2f _H On the other hand, in the case of a digital signal, the voice is usually digitized at a speed of about 64 kb / s. Therefore, it is necessary to read the scale of the horizontal axis in FIG. However, the relation of the above equation holds in this case as well.

In addition, from the mobile radio 100 to the radio base station 3
The control signal input to 0 is input to the wireless reception circuit 35, part of its output is input to the control unit 40, and the other is sent to the signal speed restoration circuit group 38 via the signal selection circuit 39. .. The latter control signal undergoes speed conversion (conversion to a low speed signal) completely opposite to that at the time of transmission, and then the general telephone network 10
The signal speed is the same as that used for the private branch exchange 17 via the signal processing unit 31.

2. Embodiment in which the present invention is applied to the connection of two private communication networks First, the function of the interface IF in FIG. 1 will be described.

The standards (parameters) of the TCM signals possessed by the two local communication networks PN1 and PN2 are assumed as follows. Time compression ratio of TCM signal r ₁ r ₂ Time length of TCM signal Time length of signal t ₁ t ₂ TCM signal multiplex number n m TCM signal frame length Signal format of T ₁ T ₂ TCM signal

The interface IF has the following functions. That is, the parameters r ₁ of the TCM signals described above are converted to r ₂ , t ₁ is converted to t ₂ , n is converted to m, and T ₁ is converted to T ₂ with respect to a signal that enters from the local area communication network PN1 to PN2. That is, the parameters of the local area communication network PN1 are converted into the unique parameters of the local area network PN2. On the other hand, with respect to a signal that enters the local communication network PN1 from the local communication network PN1, the above items 1 to 3 are converted into parameters unique to the local communication network PN1.

A specific circuit configuration for executing the following conversion will be described below. The operation principle of this circuit is, in one word, after reproducing the original signal from the TCM signal input from the local area network PN1, the TCM signal is created again using the standard (parameter) specific to the local area network PN2. While transmitting to the private branch exchange 17-2 of the private branch network PN2,
After reproducing the original signal from the TCM signal input from the local area communication network PN2, the TCM signal is created again using the TCM conversion parameter unique to the local area network PN1.
1 to the private branch exchange 17-1.

FIG. 10 shows a circuit configuration diagram of an embodiment of the interface IF. Since the configuration is symmetrical on the left and right of the dashed-dotted line in the center of FIG. 10, a detailed circuit configuration diagram of the circuit on the right half thereof is shown in FIG. The operation will be described with reference to FIGS. 10 and 11.

A local communication network P on the right side of FIGS. 10 and 11.
T sent from N1 to the local communication network PN2 on the left
Suppose a CM signal comes in. This signal is received by the signal receiving circuit 3
After being received at 35a and amplified to an appropriate level, one part goes to the control section 340a and the clock regenerator 341a, and the other part goes to many signal selection circuits 339a, eg five.
Signal selection circuit 33 including -1 to 339a-5 (FIG. 11)
9a respectively. As for the signal sent to the control unit 340a, a control signal included in the signal is extracted and used as control information necessary for control. Clock regenerator 3
When the signal is sent to 41a, the clock included in the signal is reproduced there and sent to the control section 340a and the timing generation circuit 342a, respectively.
The latter are each used for timing generation. It is natural that the system parameters of the local area communication network PN1 are used for the operation of each of these units.

The signal sent to the signal selection circuit group 339a is subjected to the same signal processing as that described in the signal selection circuit group 39 of FIG. 4, and then many, for example, five signal speed restoration circuits 338a- 1-338a-5 (see FIG. 1
1) It is sent to the signal speed restoration circuit group 338a. The operation of the signal speed restoration circuit group 338a is also similar to that already described for the signal speed restoration circuit group 38 in FIG. 4, in which processing is performed and the transmitted original signal is reproduced.
Therefore, again, T according to the system parameter of the local area communication network PN2
Signal speed conversion circuit group 351b for undergoing CM conversion processing
Sent to.

This is the end of the role of the control section 340a.
The operation of the signal speed conversion circuit group 351b is managed by the control unit 340b. That is, the operation of the control unit 340b is controlled by the control signal included in the TCM signal sent from the private network PN2 on the left side of FIG. 10 to the private network PN1. TC from the local communication network PN2
The M signal is received by the signal receiving circuit 335b and amplified to an appropriate level, then part of it is sent to the control section 340b and the clock regenerator 341b, and the other is sent to the signal selection circuit group 339b. As for the signal sent to the control unit 340b, the control signal included in the signal is taken out and used as control information necessary for control. When the signal is sent to the clock regenerator 341b, the clock included in the signal is regenerated, and the clock is sent to the control unit 340b and the timing generation circuit 342b, respectively, the former for control operation and the latter for timing generation. Used respectively.

Now, the operation of the signal speed conversion circuit group 351b, which is controlled by the control unit 340b, is performed by the system parameter used in the private network PN2. That is, the operation of the signal speed conversion circuit group 351b is similar to that of the signal speed conversion circuit group 51 described above. The time compression ratio of the signal is r ₂ instead of r ₁ , and the signal speed restoration circuit group 338 a
The original audio signal (the same applies to the image and data signals) is reconstructed from the original audio signal and separated. It is performed at t ₂ instead of t ₁ of the time piece signal. This output is sent to the signal allocation circuit group 352b and undergoes the same signal processing as the signal allocation circuit group 52 of FIG. The signal processing here is
The number of multiplexed TCM signals is n, and the frame length of the TCM signals is T ₂ instead of T ₁ . As the guard time length, the value used in the local area network PN2 is used. This output is sent to the signal transmission circuit 332b. In the signal transmission circuit 332b, amplification is performed in order to compensate for the level required for signal reception of the private branch exchange 17-2 of the private branch network PN2, and control signals similar to those used in the private branch network PN2, etc. Is added. As a result, TCM
All the signal formats of the signals will be unified to the local area network PN2.

Although the above description is for the TCM signal sent from the local communication network PN1 to the local communication network PN2, conversely the same applies to the TCM signal sent from the local communication network PN2 to the local communication network PN1. Signal conversion is performed. However, in this case, the operation of each unit is performed with a value obtained by exactly reversing the method parameter.

Also, in the signal speed conversion circuit group 351a and the signal allocation circuit group 352a, as shown in FIG. 11, many signal speed conversion circuit groups 351a-1 are provided, for example.
-351a-5 and signal allocation circuit group 352a-1
352a-5 is included.

FIG. 12 shows a situation in which time slots are exchanged via the interface IF between the private network PN1 and PN2. Here, the case where the number of multiplexing is 5 out of the functions of the interface IF is shown. This value is an example and may be any value. Further, the positions of the five time slots in the frame are set at the beginning of the frame, but this is also an example, and the positions may be set at arbitrary positions. However, each local communication network PN1, PN
Both have the same frame structure of the TCM signal used in each network.
Slots should be used for network connections without using them, except when traffic is congested.

The local area communication networks PN1 and PN2 shown in FIG.
The system parameters of are shown in the following cases. i) Time compression ratio of TCM signal ... PN1 is higher than PN2 ii) Time length of TCM signal time piece signal ... Assumed to be the same iii) Number of multiplexed TCM signals・ ・ ・ ・ ・ ・ ・ ・ ・ Assuming that PN1 is higher than PN2 iv) Frame length of TCM signal ・ ・ ・ ・ ・ ・ Assumed to be the same v) Signal format of TCM signal ・ ・ ・..Assume that control signals are inserted in each time slot

In FIG. 12, TC on the local communication network PN1 side
Since the compression rate of the M signal is higher than that on the private network PN2 side, the time slots S1-1 to S on the private communication network PN1 side.
1-5 and toward the time t ₁ of the width of S21-1~S21-5 is local network PN2 side time slot S12-
1 to S12-5 and S2-1 to S2-5 width time t
_It is smaller than ₂ . Time slots S1-1 to S1-5 from the local area network PN1 correspond to the local area network PN2.
To the time slot S12-1 to S12-
5, and when the time slots S2-1 to S2-5 from the local communication network PN2 side are sent to the local communication network PN1 side, they are converted into time slots S21-1 to S21-5. However, since the time compression rate of the signal, the location of the allocated time slot, or the number of multiplexed TCM signals are different between the two internal communication networks PN1 and PN2, a slight signal delay occurs at the interface IF, but this does not stop. I don't get it. However, this amount of delay is generally smaller than the amount of delay that occurs when connecting through the public telephone network 10, so the advantage of the present invention does not change.

As a result of the operation of the interface IF as described above, each operation in the local communication network PN2 of a signal to enter from the local communication network PN1 to the local communication network PN2 is performed by the local communication network P.
The operation of each signal peculiar to N2 is exactly the same as that of each signal. On the other hand, each operation in the local communication network PN2 that gets into the local communication network PN1 from the local communication network PN2 is exactly the same as each operation unique to the local communication network PN2. Communication between the local communication network PN1 and the local communication network PN2 is completely possible.

In the above description, the local communication networks PN1 and PN
The TCM signals used in Section 2 have been described assuming only analog telephone signals. Moreover, although the wireless system has been described as a representative, the present invention can be similarly applied to a wired telephone system. However, it is obvious that the wired telephone system does not require a conversion circuit for converting to a radio signal and a conversion circuit for converting from a radio signal. The above is for simplifying the explanation, and it is not necessary to limit the analog telephone signal. That is, a signal obtained by converting a non-telephone signal such as an image or a facsimile into a TCM signal is also applicable, and may be a digital data signal. Due to the operation of the interface IF, the signal to enter from the private network PN1 to the private network PN2 is the private network P
The signal format used in N2, and the private network PN
The signals from 2 to PN1 are converted into the signal format used in the local area network PN1.

[0072]

As is apparent from the above description, in the two local area communication networks, it is possible to directly communicate from one side to the other side without passing through the public communication network interface. The problem of detours can be eliminated, the possibility of deterioration of signal transmission quality and the occurrence of transmission delay are reduced, and then the problem of billing (use fee) associated with using a public communication network disappears. Since the circuit can be operated economically, the effect of the present invention is great.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram showing a concept of a system when the present invention is applied to two local area communication networks.

FIG. 2 is a configuration diagram of only a wireless system of one local area communication network for explaining the principle of the present invention.

FIG. 3 is a circuit configuration diagram of a mobile wireless device for explaining the principle of the present invention.

FIG. 4 is a circuit configuration diagram of a radio base station for explaining the principle of the present invention.

FIG. 5 is a time slot structure diagram for explaining time slots used in the system of FIGS. 1 to 4;

FIG. 6 is a spectrum diagram showing spectra of a call signal and a control signal.

FIG. 7 is a circuit configuration diagram for multiplexing a voice signal and a data signal.

FIG. 8 is a waveform diagram showing a radio signal waveform of a time slot.

FIG. 9 is a spectrum diagram showing spectra of a time-compressed speech signal and control signal.

FIG. 10 is a circuit configuration diagram of an interface which is an important component of FIG.

11 is a detailed circuit configuration diagram of an interface portion of FIG.

FIG. 12 is a time slot structure diagram exchanged between two local area networks via an interface.

[Explanation of symbols]

 10 telephone network 17 private branch exchange 20 barrier exchange 22-1 to 22-n communication signal 30 radio base station 31 signal processing unit 32 radio transmission circuit 38 signal speed restoration circuit group 39 signal selection circuit group 40 control unit 41 clock generator 42 timing Generation circuit 51 Signal speed conversion circuit group 52 Signal allocation circuit group 91 Digital encoding circuit 92 Multiplex conversion circuit 100, 100-1 to 100-n Mobile radio 101 Phone section 120 Reference crystal oscillator 121-1, 121-2 Synthesizer 122 -1,122-2 Switch 123 Transmission / reception gating controller 131 Speed conversion circuit 132 Radio transmission circuit 133 Transmission mixer 134 Transmission section 135 Radio reception circuit 136 Reception mixer 137 Reception section 138 Speed restoration circuit 141 Clock regenerator 200 Telephone 332 Signal transmission circuit 335 Signal receiving circuit 338 Signal speed restoration circuit group 339 Signal selection circuit group 340 Control unit 341 Clock regenerator 342 Timing generation circuit 351 Signal speed conversion circuit group 352 Signal allocation circuit group IF interface PN Private network

Claims (1)

[Claims] 1. A first and a second, each of which includes at least one of a plurality of wired terminals and a mobile wireless terminal.
Each of the private network means uses a signal which is time-compressed and divided into time slots of frame structure according to the respective standards, and the time slots of frame structure from the first private network means are used. The original signal is decompressed by decompressing it in time and decompressing the decompressed signal into a time slot having a frame structure according to the standard of the second private network means. A divided signal is generated and transmitted to the second local communication network means, and the compressed signal is temporally compressed into the time slot of the frame structure from the second local communication network means to obtain the original signal. And decompressing the reconstructed signal into a time slot having a frame structure in accordance with the standard of the first local area network means to create a delimited signal. Time division communication method in local area network to be transmitted to the serial second local area network means.