JPS5950690A - Folding system in intra-office - Google Patents

Abstract

PURPOSE:To realize a folding in an intra-office of a line concentrator for a remote subscriber in economical way, by providing a folding circuit at an internal highway so as to control the folding with a pattern on an ROM corresponding to the characteristic of a PCM transmission line. CONSTITUTION:The folding circuit DTIF is provided to the internal highway WH. The output of a folding memory is read out at all times with a delay of, e.g., 16 TS and inputted to the selector of a next stage. The other input of the selector is connected to an outgoing highway DHW from a PCM interface digital truck DT and the switching signal of the selector is controlled with the output of a control ROM. Thus, in writing a data in advance so that an output of a 4-bit word of the ROM generates a prescribed pattern in synchronizing with the TS, the changeover is attained so as the memory output is given to the remote subscriber line concentrator RLC only when the selector receives the folding TS with this data.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a digital time-division remote concentrator, and in particular, to a remote subscriber concentrator installed for a group of subscribers in a remote location. This relates to a call back method within the local station for establishing a communication path.

(2) Background of the technology In general, digital time-division switching equipment has good compatibility with PCM transmission lines, and remote subscriber line concentrators (hereinafter referred to as rRLcj) are installed for subscriber groups in remote areas, and they connect to the RL C. It is common that the terminal is connected to a private-level exchange (hereinafter simply referred to as "I master station") via a PCM transmission line.

(3) Prior art and problems Figure 1 is an explanatory diagram of a remote subscriber line concentrator in a digital time division switch.
accommodates subscribers, and is connected to the communication path network of the master station by a PCM transmission path.

FIG. 2 is a block diagram of the main parts of a remote line concentrator in which the present invention is implemented.

In FIG. 2, SLC is a subscriber circuit provided for each subscriber, and also has an A/]:If conversion function. M
PX is a multiplexer and multiple subscriber circuits SLC
information signals are time-division multiplexed.

DMPX is a demultiplexer and distributes the multiplexed signal to each subscriber circuit SLC. The USPM and DSPM are controlled by the upper multi-directional and downstream audio memories, and controlled by the line concentrator processing unit (LPR), and are connected to the upper multi-directional highway UHWi and the lower multi-directional highway via the demultiplexer DMPX and multiplexer MPX, respectively. DHWi is multiplexed to each of the four highways.

DT is a digital trunk for PCM interface, D
TCii, DT common part is shown.

RLC has a dedicated processing unit LPR, controls the status of subscribers, communicates with the master station, and according to instructions from the master station MPX,
A call path is set by controlling the DMPX, writing the voice of a specific subscriber to a specific address of the USPM, and distributing the voice data read from the specific address of the DSPM to the subscriber.

There is also a DMPX on the PCM transmission line side of USPM and DSPM.
/ MPX, converted to 4 internal highways (HW) of 2.048 Mb/s 32 time slots and DTC
, DT to interface with the PCM transmission path.

That is, for up to 1920 subscribers, USPM.

Each DSPM has 128 (32
SPM.

The line concentration function is realized by allocating it to a vacant address in the DSPM.

DMPX/MP on the PCM transmission line side of USPM/DSPM
X only statically decomposes/focuses 128 channels into 32×4, and there is no dynamic control.

Now, the internal HW of 2.048Mb/s x 4 is D
It is connected to the DT via the TC and interfaces with the PCM transmission line, but as mentioned earlier, when the proportion of RLC calls within its own station is high, it is the PC that performs the callback via the master station.
M transmission path is uneconomical, and if loopback can be performed within RLC, the PCM transmission line and DT used for loopback can be deleted. If it is implemented and the channel corresponding to the non-implemented DT can be used in the RLC local station, the economic effect will be great.

FIG. 3 is an explanatory diagram for explaining the principle of the local loopback system in the remote line concentrator of the present invention.

Among the codes shown in Fig. 3, the same codes as in Fig. 2 = 3- indicate the same content.

RLC call back within the local station is performed by subscriber A who is making a call within the local station.
and subscriber B in the same internal HW) (T
S) This is realized by assigning to two separate TSs.

The subscription report (voice data of A) on the USPM is assigned to <TS(n)> of the QUHW under the control of the LPR.

This voice data is stored in 16TS by loopback memory within the local station.
+α (α: Fixed time difference between upper and lower combs) delay, I) HW <TS(n+16)). Similarly, under the control of the LPR, subscriber A's voice data assigned to TS(n+16) is written to subscriber B's location in the DSPM. According to the above procedure, subscriber A's voice is transmitted to subscriber BK.
I can hear it.

On the other hand, subscriber B's voice data on USPM is LPR
According to the specification, the audio data assigned to (TS(n+16)) of 9UHW is stored in the local loopback memory on the pDH.
<TS (n+ 16+ 16)>(-<T
5(n)>) and similarly fi is specified by LPR.
The voice of DsPM 4-B can be heard by subscriber A, and it becomes possible for subscriber A and subscriber B to talk to each other.

For example, when connecting to a master station using 2,048 Mb/s PCM, which is currently commonly used in other countries, the channel on the internal HW and PCM transmission path is -1: or It corresponds to 1. which is standard in Japan and the United States.
When connected to a 544 Mb/s 24 channel position M transmission line, the channel position must be converted in the DTC section, and the return channel due to deletion of the physical link/DT is no longer limited to only one internal HW. , PCM transmission line is 2.048Mb/s 32TS
In the case of 30CH, if one of the transmission lines is not installed to be used for loopback, the internal HW will also loop back two TSs 6TS apart in the IHW in order to fully correspond with the corresponding internal HW. However, when interfacing with PCM transmission lines with different multiplicity, for example, 2.048Mb/s 30CHX4Hw for i4 and DTC.
4-+1.544Mb/s 24CHX51ink
CH (
TS) and the link number of the CH on the PCM link corresponding to it usually do not match.

FIG. 4 shows the relationship between PCM24LinkCH and RLCHW. Here, PCM IJ link is 1.544Mb/
This is a case where the NHW within s is 2.048 Mb/s.

If PCM link A4 (DT4) is not implemented here, the RLC internal TireSlot used for loopback will be distributed between I(WO and HW3). do.

In the conventional system, only the concentration control of subscriber lines is performed by RLC, and even if the calling party and the called party are accommodated in 1-bit J-RLC, the communication path is routed through the communication path network of the master station. Connected. That is, even in the case of an RLC intra-station call, two communication channels are used on the PCM transmission path between the RLC and the master station. Therefore, even if the ratio of RLC calls within the local station is higher than calls outside the RLC local station, a PCM transmission path is prepared between the base station and the base station for the sum of the two call volumes. There was a problem in achieving economic efficiency.

Furthermore, when the channel is looped back without installing a PCM transmission path, it has been common to provide a loopback circuit on the PCM side. However, if the channels on the PCM are folded into odd channels and even channels, the corresponding internal HW will not be able to perform pair control, resulting in an increase in control memory, and the loop will be folded back to 120H, which corresponds to 1/2 frame. Since the PCM24 has one synchronization bit at the beginning of the frame, the amount of delay to recover varies depending on the channel, and in any case, it was a cine economy with complicated hardware.

(4) Purpose of the Invention The present invention (in view of the conventional drawbacks in terms of performance, relieves these drawbacks of the conventional remote subscriber concentrator connection FDLI control method,
Even when the internal HW and PCM transmission scheme do not match (irrespective of the mismatch), remote power [one-person line concentrator itself] can be transmitted in a simple and economical way without going through the communication path network of the master station. The purpose of this invention is to provide a method for returning calls within the local station by which it is possible to establish an ITB channel for a call.

(5) Structure and object of the invention According to the present invention, there are M internal HWs with a capacity of m channels, and a maximum of N PCM lines with a capacity of n channels.
When the relationship mXM=nXN holds in a time-sharing remote line concentrator that is connected to the master station in real time, each internal HW
A means is provided to switch channels that are separated by a distance of 1.0 mm, and when there is a line that is not physically prepared among the PCM lines of the line concentrator, the n channels that are connected to the line are connected to 7 calls by the above means. This is achieved by providing an intra-office loopback method characterized in that the remote concentrator is used for intra-office calls.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 5 shows a block diagram of an RLC implementing the present invention.

A feature of the present invention is that in order to achieve independent control from the PCM transmission path, a folding circuit DTiF is provided on the internal 1-IW side, which corresponds to the characteristics of the PCM transmission 1b. The loopback is controlled based on the pattern.

FIG. 6 is a block diagram of the return control section (for simplicity, 1
Only the Hw is shown, but the same goes for the remaining jllll 3 Hw) The UHW from the LC is always written in the return memory at the same time as it goes to the DT.

Similarly, the output of the folding memory is always read out with a delay of 16 TS and input to the next stage selector. The other input of this selector is DHW from DT is v#J'
r, and the selector switching signal S is controlled by the output of the CTLROM.

Now, if DT4 is not installed in PCM24, DHWO's TS2, 7, 12, 18, 23, 28° DH as shown in Figure 4.
WI's TS3, 8, 13, 19, 24, 29° DHW2
TS4, 9, 14, 20, 25, 30° DHW3 T
S5, 10, 15, 21, 26, 31° are T for folding
It becomes S.

FIG. 7 is a sequence diagram of the pattern information that generates the output of the control ROM (CTLROM) in FIG.
) is not installed with Digital Trunk 4 (DT4), (
b) is when Digital Trunk 3.4 (DT3.DT4) is not installed, (C) is when Digital Trunk 2.3.4 (
DT2. DT3. DT4) Shows the case when not installed.

Therefore, if data is written in advance so that the output of the 4-bit word of the ROM synchronizes with the TS and generates a pattern as shown in FIG. Only the loopback memory output is RL.
It is possible to switch to flow to C.

Similarly, if DT3.4 is not installed, if a pattern as shown in FIG. 7(b) is generated, the corresponding TS of each internal DHW is switched to the output from the loopback memory.

In this way, in order to generate different patterns depending on the DT mounting conditions, the DT non-installation information is input to the upper address of the control ROA/1, and the lower address is manually inputted with a counter output synchronized with the TS.

For the sake of explanation, we have taken the case where the PCM24 is connected to the master station as an example, but in the case of the PCM30 as well, by setting the ROM pattern to all'''1'' for the internal HW corresponding to the non-equipped DT, It is clear that this can be achieved without changing the clothing at all.

(6) Effects of the Invention As explained in detail above, the local loopback method of the present invention allows the multiplicity of the internal HW to match the multiplicity of the PCM transmission line.
Regardless of the discrepancy, it is possible to implement II LC local loopback economically and uniformly using simple hardware, which is very effective.

[Brief explanation of the drawing]

Figure 1 shows the activation and disconnection of a remote subscriber line concentrator in a digital time-division exchange to which the present invention is applied, Figure 2 is a block diagram of the main parts of the remote line concentrator, and Figure 3 shows how the remote line concentrator returns within its own station. Principle diagram of the system, Figure 4: PCM24Li
nk CH and RLCHW, FIG. 5 is a block diagram of a remote line concentrator to which the local loopback 17 method according to the present invention is applied, FIG. 6 is a block diagram of the loopback connection section shown in FIG. Figure 7 is the ROM for discount 1 shown in Figure 6.
(CTLROM) 11- is a sequence diagram of pattern information in which an output is generated. In the drawing, RLC is a remote line concentrator, NW is a channel network, SLC is a subscriber circuit, MPX is a multiplexer, DMPX is a demultiplexer, USPM is an upper multi-directional voice memory, and DSPM is a downstream voice memo! J.LP
R is processing unit for line concentrator, DT is digital trunk,
DTCUDT common area, UHW is upper multi-directional highway, D
HW is lower multi-directional highway, CTL ROM is R for control
OM, R, CNT12-

Claims (1)

[Claims] In a time-sharing remote concentrator that has M internal HWs with a capacity of m channels and is connected to a master station through N PCM circuits with a capacity of n channels, when the relationship mXM = nXN is established again. , a means is provided in each internal HW to switch between channels that are far apart, and the PCW of the line concentrator is
When there is a circuit section that is not physically prepared in the circuit string, n channels that are not connected to the circuit are used by the above means for one call within the remote concentrator's own station. Folding method.