JPS59178894A - Line concentration and distribution system - Google Patents

Abstract

PURPOSE:To prevent two signals transmitted from a line concentration and distribution device from being collided with each other nor idle space from being formed by transmitting a signal to a central device a prescribed time after all the line concentration and distribution devices receive the signal addressed to the own device from a central device. CONSTITUTION:Telephone sets 30Aa, 30Ab, and 30Ac are connected to the line concentration and distribution device 31A. A signal from the line concentration and distribution devices 31A, 31B, 31C and 31D are subjected to time division and multiplex from leading paths 32A, 32B, 32C and 32D via a line concentration transmission line 33 to a central device 34. On the other hand, a signal from the central device 34 is subjected to a time division multiplex signal through the distribution transmission line 35 to the line concentration and distribution devices 31A, 31B, 31C and 31D from leading paths 36A, 36B, 36C and 36D. The 39A, 39B, and 39C are delay circuits. A synchronizing signal detection circuit 44 separates and extracts correctly the signal transmitted to the own device by detecting the synchronizing signal component among the signals transmitted to the line concentration and distribution device 31A. Thus, the distribution circuit 45 receives correctly the data signal part and separates and distributes a signal to each terminal from said signal.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention is directed to transmitting data generated at multiple locations to a central device in a time-sharing manner over one transmission path, and transmitting data from the central device to a central device. This paper relates to a line concentration and distribution system in which gold and other metals are sent to multiple locations in a time-division manner on one transmission line.

[Technical background of the invention and its problems]

For example, in a private branch exchange (PBX), it is extremely difficult to run wiring from all buildings or floors to the PBX. Therefore, a method can be considered in which a line concentrator is provided for each building or floor, as shown in FIG. 1, and all the voice data concentrated there is sent on one bus to the switch control section of the solid equipment. 1a, lb...1n in FIG. 1 are terminals such as telephones.

2a, 2b, 2e are line concentrators and distributors, multiplexer and distributors 3a, 3b, 3c and transmitters 4a, 4b.
, '4c and receivers 5a, 5b, 5c.

Signals from the terminals are time-division multiplexed by a multiplexer and distributor and then transmitted from a transmitter. The time-division signal received by the receiver is distributed by a multiplexer/distributor into signals for each terminal and sent to each terminal. The multiplexer and distributor includes an AD converter or DA for converting analog and digital signals.
Assume that a converter is also included. Further, a transmitter includes all transmitting circuits including a modulator, and a receiver includes all receiving circuits including a demodulator. Transmitter 4a, 4b, 4c
From there, signals are sent to the concentrator transmission line 7 through introduction lines 6a, 6b, and 6ck. The signal on the concentrator transmission line 7 is sent to the receiver 8
and sent to the exchange control section 9. Signals going from the exchange control unit 9 to each terminal are sent from the distribution transmission line 11 through the transmitter 10' (i=) to the receivers 5a, 5b, 5c through the introduction lines 12a, 12b, 12ck.Receiver 8
．． The transmitter 10 and the exchange control unit 9 are connected to a solid device 13. The signals on the concentrator transmission line 7 and the distribution transmission line 11 may be baseband or carrier band. Transmitter 4a-4
C, 10, receivers 5a-5c, 8 have circuits according to the above.

FIG. 2 is a time relationship diagram of signals on a transmission path.

(A) is a signal on the distribution transmission path at the position of the transmitter 10. SOa is a synchronization signal portion of the signal going to the line concentrator/distributor 2a, and DOa is also a data signal portion. Assume that the line concentrator/distributor sends out a signal to the line concentrator transmission line 7 through the lead-in path 12a as soon as it finishes receiving the synchronization signal portion SOa. FIGS. 2(B), 2(C), and 2(E) show signals on the concentrated transmission line at the position of the receiver 8. It is assumed that the transmission delay time from one end of the concentrating transmission line or the distribution transmission line to the other is -6tz.

If the concentrator/distributor 2a is connected to the concentrator transmission line 7 and the distribution transmission line 11 at the point closest to the receiver 8 and transmitter 10 (temporarily called a near-end point), then the input of the receiver 8 The signal from the line concentrator/distributor 2a on the line concentrator transmission line 7 is as shown in FIG. 2(b). Further, the line concentration distribution device 2a connects the receiver 8 and the transmitter 10 to the line concentration transmission line 7 and the distribution transmission line 11.
If the connection is made at the farthest point (temporarily called the far end point) from , there is a time difference of only 2tt between (b) and (c). It is assumed that each line concentrator/distributor may be attached at any point on the transmission path. For example, assume that the line concentrator/distributor 2a is connected to the far end point of the transmission line, and the line concentrator/distributor 2b is connected to the near end point of the cable. As shown in FIG. 2(a), the signals (synchronization signal SOa, data signal SOa) going to the line concentrator/distributor 2a and the signals (synchronization signal sob, data signal sob) going to the line concentrator/distributor 2b, which are carried on the distribution transmission line 11, are Assuming that there is a space time of 27 between them, the signals (synchronization signal SIb, data signal DIb) on the concentrator transmission line 7 at the near end point coming from the concentrator/distributor 2b are shown in FIG.
The time relationship between the signals coming from the two line concentrators and distributors 2a and 2b is as shown in FIG. 2 (e). If the space time shown in FIG. 2(A) is smaller than 212, DIa and SIb will collide and the receiver 10 will not be able to receive correct conversion. Therefore, on the distribution cable, the space time between signals going to each concentrator/distributor must be made thicker than 2tt, and if the transmission path length is long, it will be 2tt.
This increases the amount of time required, making it necessary to take up a large amount of space. Therefore, the percentage of time during which signals can actually be sent decreases, and the number of line concentrators that can be connected to a pair of transmission paths decreases.

[Purpose of the invention]

In order to eliminate the above-mentioned inconvenience, the present invention defines the order of the signals transmitted from the solid equipment so that the two signals sent from the concentrator and distribution equipment do not collide, and also eliminates unnecessary space. This is to ensure that there are no errors.

[Summary of the invention]

The signals sent from the solid equipment to the line concentrator/distributor are time-divisionally arranged in the order of the shortest distance of the transmission path from the solid device to the line concentrator/distributor (in other words, in the order of the shortest round-trip signal transmission delay time), and From the solid equipment to the farthest line concentrator/distributor as the time space from when the signal is sent to the farthest line concentrator/distributor until the signal starts to be sent to the nearest line concentrator/distributor. The difference in the round-trip signal transmission delay time between The feature of the line concentration and distribution system of the present invention is that it transmits actual device signals.

〔Effect of the invention〕

According to the present invention, the signals transmitted from the line concentrator to the solid device do not collide with each other, and the space between two signals does not become excessive, so that transmission efficiency can be improved.

[Embodiments of the invention]

FIG. 3 shows an embodiment of the present invention. FIG. 4 shows a waveform diagram of each part of FIG. 3. Telephone 30Aa, 30Ab, '30Ac
is connected to the line concentrator/distributor 31A. Signals from the concentrators and distributors 31A, 31B, 31C, and 31D are routed through the introduction path 3.
2A, 32B.

From 32C and 32D, the signals pass through the concentrator transmission line 33 in a time-division multiplexed manner and go to the middle mounting [34]. On the other hand, the signal from the solid equipment 34 passes through the distribution transmission line 35 as a time-division multiplexed signal and is sent from the introduction lines 36A, 36B, 36C, and 36D to the concentrators and distributors 31A, 31B, 31C, and 31D. There is a switch 37 in the solid equipment 34, from which signals going to each concentrator/distributor are simultaneously sent to 38A and 38B.
, 38C.

38D. The timing of this output is shown in FIG. 4(a). Here, as a representative, signal SO
a, DOa e is shown. 39A, 39B, 3
9C is a delay circuit. If the time required to transmit one signal is tw, each delay time is 3 tw
, 2tw.

It is ltw. This delay circuit may be a shift register, or a RAM may be used to temporarily store and control the readout time. 38D and delay circuit output 40
The outputs of C, 40B, and 40A are as shown in FIG. 4 (B) 0, C), and (E), respectively. 41 is a time division multiplexing device which time division multiplexes four inputs to produce a multiplexed signal as shown in FIG.
Output to 5. In the concentrator/distributor 3LA, the distribution transmission line 35
A receiver 43 receives the signal that has passed through the introduction path 36Ak, and sends it to a synchronization signal detection circuit 44 and a distribution circuit 45. The synchronization signal detection circuit 44 correctly separates and extracts the signal sent to itself by detecting the synchronization signal portion SOa f of the signal sent to the line concentrator and distribution device 31A.

As a result, the distribution circuit 45 correctly receives the data signal portion DOa, and separates and distributes the signals going to each terminal from this signal. 46 is a terminal electronic interface circuit; if the terminal is a telephone, a circuit that converts the signal from the distribution device into an analog signal by DA converting it, and a circuit that converts the signal from the telephone into an analog signal and converts it into a digital signal and sends it to the multiplexing circuit 47; , hybrid transformer, etc. are all included. Signals from each terminal are time-division multiplexed by a multiplexing circuit 47 to become a data signal portion DIa. When the synchronization signal detection circuit detects SOa 5, the multiplexing circuit 47 adds the synchronization signal part SIa to the data signal part DIa, and transmits it to the transmitter 48. It is sent to the concentrator transmission line 33 via the introduction line 32A. Other line concentration distribution device 31B,
31C and 31D are also configured with similar circuits. From the solid device 34 to each concentrator/distributor 31D, 31C.

For example, the one-way transmission delay time to 31B and 31A is △, 3
△.

If 5△, 6△ (△ is a certain unit time), the solid device 34 is
The timing of the signal sent towards is shown in Figure 4 (G).
(to).

((6).Each signal undergoes a transmission delay in the concentrator transmission line, so from the concentrator transmission line 33 to the solid device 3.
The multiplexed signal when input to 4 becomes as shown in FIG. 4, Q→. The above signal passes through the receiver 49 in the solid equipment 34, is distributed by the distribution circuit 50 into signals for each concentrator/distributor or each terminal, and is supplied to the exchange 37. Fourth
As shown in Figure Q→, each signal overlaps (@collision) (d does not occur. Also, the time tR may be 0 with some margin. At this time, the time tR may be 0. ) space time ts is the round-trip signal transmission delay time tOD between the middle mounting R34 and the nearest concentrator/distributor 31b, and the round-trip signal transmission delay time tOA between the solid device 34 and the farthest concentrator/distributor 31A. (toA-toD), that is, tS〉
If tOA toD, tR>O and concentration distribution &ft
The signal from f3iA and the signal from f31D do not collide.

In addition, the signal from each concentrator to the solid device was supposed to be sent as soon as the synchronization signal part of the signal intended for it was received, but even if it was sent after a fixed period of time, it could be interrupted at any time. do not have.

Further, the concentrating transmission line and the distribution transmission line may be separate cables, or a single cable may be used by dividing the band.

The signals on these transmission paths may be baseband or carrier band.

As described above, the present invention is not limited to the embodiments.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a conventional line concentration distribution system, Fig. 2 is a time diagram for fully explaining Fig. 1, Fig. 3 is a diagram showing an embodiment of the present invention, and Fig. 4 is an explanation of Fig. 3. This is a time diagram for

Claims (2)

[Claims] (1) Time-divisionally multiplexed signals are sent from the central device to a plurality of line concentration distribution terminals through a first transmission path, and time-division multiplexed signals are sent from the plurality of line concentration and distribution terminals to the central device through another transmission path. A concentrating and distributing system that multiplexes signals to each concentrating and distributing device and returns signals from the solid device to each concentrating and distributing device in the order of shortest transmission path distance from the solid device to each concentrating and distributing device. A line concentration distribution system characterized in that transmission is performed in a time-division multiplex arrangement, and each line concentration and distribution device transmits a signal to the central transmission after a predetermined period of time after receiving the signal for itself. (2) The time interval from the end of sending a signal to the concentrator/distributor whose transmission line is farthest until the time when the signal begins to be sent to the concentrator/distributor whose transmission line is closest is from the central unit to both concentrators/distributors. The line concentration distribution system according to claim 1, wherein the difference in signal transmission delay time between round trips is greater than or equal to the difference in signal transmission delay time between round trips.