JP2568538B2 - Subscriber line signal line multiplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Signals from a plurality of subscriber-side terminating devices of a digital integrated service network (hereinafter referred to as ISDN) are condensed and multiplexed and sent to an exchange, thereby providing a line to the exchange. Reduce the number,
An economic system can be constructed.

[Industrial applications]

The present invention is directed to ISDN, in particular, a wideband ISDN using a videophone or the like.
The present invention relates to a subscriber line signal concentrator / multiplexer for concentrating and multiplexing signals from a plurality of subscriber terminating units and sending the multiplexed signal to an exchange.

In the early stage of wideband ISDN construction, subscribers are scattered on a nationwide scale, the distance to the central exchange is long, and subscribers use the line less frequently.

In such a case, it is desired to provide a subscriber line signal concentrator which can make the subscriber line signal processing system between the subscriber side terminating device and the exchange economical.

[Conventional technology]

 Hereinafter, a conventional example will be described with reference to the drawings.

FIG. 6 is a configuration diagram of a conventional subscriber line signal processing system.

In FIG. 6, point-to-point subscriber terminals 1-1,2-1 and point-to-multipoint subscriber terminals 3-1,3-1,4-1,4-2 are scattered throughout the country. The signal is transmitted to each of the subscriber terminating units 1, 2, 3, and 4 as shown in FIG. 3A, where a service identification code for identifying a data packet or a call control packet is provided. 70, and a termination point identifier for identifying the subscriber terminal, and a termination point identifier 71, and communication information 72 are sent to the exchange 10 'via separate lines 31, 32, 33, and 34 as a frame format.

In the exchange 10 ', these signals are converted by the subscriber line signal processors 11, 12, 13, and 14 into a call control packet, a data packet, and a signal from which subscriber. Recognize and process.

[Problems to be solved by the invention]

However, in the configuration of the subscriber line signal processing system as described above, the line to the exchange 10 'is connected to the subscriber side terminating device.
It is necessary for each of 1,2,3,4, and there is a problem that the price as a system becomes high.

[Means for solving the problem]

 FIG. 1 is a block diagram showing the principle of the present invention.

The subscribers 1, 2, 3, and 4 shown in FIG. 1 each accommodate one or more subscriber terminals and transmit a signal frame provided with a termination point identifier as identification information of the subscriber terminal to the exchange 10. This is the user-side terminal device.

20 is provided between a plurality of subscriber terminating devices 1, 2, 3, 4,... To which one or a plurality of subscriber terminals are connected, and a line connected to the exchange 10, respectively. A subscriber line signal concentrator / multiplexer that receives and relays a signal transmitted / received between the terminal equipment and the exchange. The received signal is transmitted from the subscriber terminal equipment to which one subscriber terminal is connected. In the case of a signal frame, instead of the terminal point identifier provided as identification information of the subscriber terminal in the signal frame, subscriber line identification information (hereinafter referred to as subscriber line number) determined for each subscriber terminal device. ) Is inserted as a line-gathering identifier, and if the received signal is a signal frame transmitted from a subscriber-side terminating device to which a plurality of subscriber terminals are connected, a line-gathering identifier is added to the signal frame. Line multiplexing of signals from the subscriber terminal And it includes therein a code converting adding means 21 for sending to the line Te.

[Action]

According to the present invention, the code conversion adding means 21 of the subscriber line signal concentrator / multiplexer 20 receives the signal frame transmitted from the subscriber side termination device to which one subscriber terminal is connected. A signal transmitted from a subscriber terminal device to which a plurality of subscriber terminals are connected, in which a subscriber line number is inserted as a concentrator instead of the termination point identifier provided as identification information of the subscriber terminal in the frame. When a frame is received, a line concentrator is added to a signal frame, and then a signal from each subscriber side terminating device is line-multiplexed and transmitted to a line. Can be configured at low cost.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of a subscriber line signal line multiplexing apparatus according to an embodiment of the present invention, FIG. 3 is a diagram showing an example of a signal frame format, and FIG. 4 is a block diagram of an example of a packet line multiplexing circuit. FIG. 5 is a block diagram of an example of a packet distribution circuit.

In FIG. 2, signals from the point-to-point subscriber terminals 1-1 and 2-1 and the point-to-multipoint subscriber terminals 3-1 and 3-2, 4-1, and 4-2 are respectively shown. As shown in FIG. 3A, service termination codes 70, 70 for identifying whether the packet is a data packet or a call control packet, as shown in FIG. And a termination point identifier for identifying the subscriber terminal, and a termination point identifier 71 and a frame format having the communication information 72 are input to the switch 22 of the subscriber line signal concentrator / multiplexer 20.

The switch 22 is initially set in advance, and this switch
At 22, the point-to-point subscriber terminals 1-1 and 2-1
The signals from the subscriber-side terminating devices 1 and 2 which accommodate the terminal are input to the packet concentrator / multiplexer / distributor circuit 23 and transmitted to the point-multipoint subscriber terminals 3-1, 3-2, 4-1 and 4-2. Signals from the subscriber-side terminating devices 3 and 4 to be accommodated are input to a packet concentrator multiplexing / distributing circuit 24, sent from the packet concentrator multiplexing / distributing circuit 23 to the exchange 10 via a line 40, and Rather, it is sent to the exchange 10 via the line 41.

The packet concentrator multiplexing / distributing circuits 23, 24 are circuits having the function of the code conversion adding means 21 shown in FIG. 1, but since both circuits are substantially the same, the packet concentrator multiplexing / distributing circuits 23, 24
Will be described first.

The packet concentrator multiplexing / distribution circuit 23 is composed of a packet concentrator / multiplexer used for transmission to the exchange 10 and a packet distribution / multiplexer used for reception from the exchanger 10, but shows a packet concentrator / multiplexer on the transmitting side. FIG. 4 shows the receiving-side packet distribution circuit, and FIG. 5 shows the receiving-side packet distribution circuit.

4 and 5, there are eight subscriber lines from the subscriber-side terminating device, the subscriber line to, the signal from the subscriber line to CH1, the signal from the subscriber line to CH2, The signal of the subscriber line ~ is put on CH3, and 3CH of CH1 ~ CH3 on the line 40
An example in which is transmitted and received after being multiplexed will be described.

In FIG. 4, signals from the subscriber line to 1: 1 corresponding to the subscriber terminal via the subscriber-side terminating device are:
The data is temporarily stored in the buffer memory 51 under the control of the receiving unit 50.

At this time, as previously determined, the stored signal is:
In the case of the subscriber line or more, the FIFO (first-in, first-out) memory 53-1 for CH1 is stored in the FIFO (first-in, first-out) memory 53-1.
In the second FIFO memory 53-2, the subscriber line number, the stored address of the buffer memory 51, the frame length, and the transmission request are written in the FIFO memory 53-3 for CH3 in the case of the subscriber line to the twister.

The transmission unit 52 sets the FIFO memories 53-1 to 5
Referring to 53-3, if there is a transmission request, the subscriber line number and the stored address of the buffer memory 51 are recognized, the signal stored in the buffer memory 51 is read out at this address, and send.

In the selector 55, under the control of the transmission unit 52, with the subscriber line number recognized by the transmission unit 52, the pattern generator 54 generates a line collection identifier indicating the subscriber line number, and under the control of the transmission unit 52, Instead of the end point identifier 71 shown in FIG. 3A and read from the buffer memory 51, a line convergence identifier generated by the pattern generator 54 is inserted, and the signal frame format of FIG. The format is abbreviated as a format), and is transmitted on the corresponding CH corresponding to the read FIFO memory.

The transmission side of the packet concentrator multiplexing / distribution circuit 24 for point-to-multipoint subscriber terminals will be described mainly with reference to FIG. FIG. 3 shows that a line concentrator 80 generated by controlling the pattern generator 54 with the subscriber line number recognized by looking at −1 to 53-3 is read from the buffer memory 51 by the selector 55 (FIG. 3). C) The frame format shown in (D) is added to the header of the frame format shown in [Same frame format as in (A)], and the frame is transmitted on the corresponding CH corresponding to the read FIFO memory.

Next, the operation of the subscriber line signal processor 10-1 of the exchange 10 which has received the signal of the frame format shown in FIG. 3B transmitted via the line 40 shown in FIG. 2 will be described. .

From the signal of the transmitted frame format, the subscriber line number corresponding to the subscriber terminal 1: 1 is recognized by the concentration identifier 80, and whether the packet is a call control packet or a data packet is determined by the service identification code 70. And performs the corresponding process.

Next, the operation of the subscriber line signal processor 10-2 of the exchange 10 which has received the signal of the frame format shown in FIG. 3D transmitted via the line 41 shown in FIG. 2 will be described. .

The subscriber line number is recognized by the concentrator identifier 80 from the transmitted frame format signal, and the termination point identifier 71
, The subscriber terminal which is connected to the subscriber line of the subscriber line number in a multi-line is identified, and whether the packet is a call control packet or a data packet is identified by the service identification code 70. Perform processing.

 Next, the receiving side will be described with reference to FIG.

In the subscriber line signal processor 10-1 shown in FIG. 2, a signal having a frame format as shown in FIG.
When any of the CHs of the 3CH multiplexing is input to the receiving unit 62 via the line 40, the receiving unit 62 applies 1: 1 to the subscriber line number of the concentrator identifier 80 recognized from the frame format regardless of any CH. Is generated by the pattern generator 64, and the selector 65 inserts the terminal point identifier 71 in place of the concentrator identifier 80 in the frame format shown in FIG. Then, it is stored in the buffer memory 61.

At this time, the receiving unit 62 stores the address, the frame length, and the transmission request stored in the buffer memory 61 in a FIFO memory corresponding to the subscriber line number recognized from the line concentrator 80, for example, 63-1.

The transmission unit 60 sets the FIFO memory 63-1 to
Referring to 63-8, if there is a transmission request, the address stored in the FIFO memory corresponding to the subscriber line number is recognized, and the signal stored in the buffer memory 61 is read at this address. , Via the subscriber line of the corresponding subscriber line number.

For point-multipoint subscriber lines,
From the subscriber line signal processor 10-2 of the exchange 10 in FIG.
Concentrator identifier indicating a subscriber line number as shown in FIG.
When a signal in a frame format in which 80 is added to the header is transmitted, the selector 65 in the receiving unit 62 shown in FIG.

At this time, the corresponding FIFO memory is selected by the subscriber line signal line multiplexer, and the address, frame length, and transmission request stored in the buffer memory 61 are stored.

Thereafter, the same operation as in the point-to-point case described above is performed, and the data is transmitted to the subscriber-side terminating device via the corresponding subscriber line.

As described above, by changing to a frame format having contents indicating the subscriber line number and the connection position of the subscriber terminal (in the case of point-point, the connection position of the subscriber terminal is known if the subscriber line number is known). And multiplexing can be performed. By performing multiplexing as described above, the second
As shown in the figure, in the case of a point-to-point subscriber terminal, the line is multiplexed and transmitted / received on a line 40, and in the case of a point-multipoint subscriber terminal, the line is multiplexed and transmitted / received on a line 41. Since the number of lines between the multiplexer 20 and the exchange 10 can be greatly reduced and the number of subscriber line signal processing devices can be significantly reduced, the system can be made very inexpensive.

〔The invention's effect〕

As described in detail above, according to the present invention, signals from a plurality of subscriber terminating devices are multiplexed and sent to an exchange through a very small number of lines, thereby providing a subscriber line signal processing device. Can be greatly reduced, and the system can be made very inexpensive.

[Brief description of the drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of a subscriber line signal multiplexing apparatus according to an embodiment of the present invention, FIG. 3 is a diagram showing an example of a signal frame format, FIG. 5 is a block diagram of an example of a packet line multiplexing circuit, FIG. 5 is a block diagram of an example of a packet distribution circuit, and FIG. 6 is a configuration diagram of a conventional subscriber line signal processing system. In the figure, 1-4 are subscriber terminating devices, 1-1,2-1,3-1,3-2,4-1,4-2 are subscriber terminals, 10,10 'are exchanges, 10- 1, 10-2, 11 to 14 are subscriber line signal processing devices, 20 is a subscriber line signal concentrator / multiplexer, 21 is code conversion adding means, 22 is a switch, 23 and 24 are packet concentrator / multiplexer circuits, 31 Reference numerals 34, 40, and 41 denote tracks.

Continued on the front page (72) Inventor Kazuo Kato 1015 Uedanaka, Nakahara-ku, Kawasaki City Inside Fujitsu Limited (72) Inventor Ichihiro Hiraide 3-9-1 Midoricho, Musashino City Nippon Telegraph and Telephone Corporation Within the research institute (72) Kinya Dezaki 3-9-1, Midoricho, Musashino-shi Nippon Telegraph and Telephone Corporation Communication Network First Research Laboratory (72) Inventor Hidetoshi Takeshita 5-33-1, Shiba, Minato-ku, Tokyo NEC Corporation In company

Claims (1)

(57) [Claims] A plurality of subscriber terminals each connected to one or a plurality of subscriber terminals and a line connected to an exchange; A signal provided between the plurality of subscriber terminating devices and the exchange, and a received signal transmitted from a subscriber terminating device connected to one subscriber terminal. If it is a frame, instead of the terminal point identifier provided as identification information of the subscriber terminal in the signal frame, the subscriber line identification information determined for each subscriber side termination device is inserted as a line collection identifier, If the received signal is a signal frame transmitted from a subscriber terminal connected to a plurality of subscriber terminals, the signal line identifier is added to the signal frame, and then the signal from each subscriber terminal is added. To be multiplexed and sent to the line Subscriber Signaling concentrator multiplexing device characterized by comprising a conversion adding means (21) (20).