JPS62253249A - Digital exchange - Google Patents

Abstract

PURPOSE:To contain digital subscriber circuits of (2B+D) in an exchange, by providing a means which discriminates circuit switching and packet switching and performs speed change or packet assemblage and disassemblage. CONSTITUTION:Digital telephone subscriber line signals of (2B+D) of two digital data B1 and B2 and one signal channel D are outputted to a subscriber line transmitting circuit 1, where the channels B1, B2, and D are separated from each other. The separated channels are respectively supplied to a microprocessor 6, ROM 7, and RAM 8 through a processor bus 5. Distinction of the line switching call and packet switching call from a subscriber is informed to the processor 6 through the channel D and the processor 6 performs a speed change in the case of the line switching call through prescribed program operations. In the case of the packet switching call, the processor 6 performs packet assemblage. Operations from an exchange side are also performed in the same manner, namely, a speed change in the case of a line switching call and packet disassemblage in the case of a packet switching call.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital exchange, and more particularly to a digital exchange that accommodates 2B10 digital subscriber lines.

[Conventional technology]

Conventionally, subscriber lines have adopted an analog transmission system, and therefore, when performing data communication, communication is performed based on analog modulation via a modem.

Recently, there has been active development of technology to perform digital transmission using this subscriber line, and one method is +44K.
b/92B+D method (64Kb/S+[4Kb/S+l
8Kb/S) was recommended as the CCrTT I series (CCITT RED BOOK VOI l1l-
FASCICCE 111.51integrated
5service Digital Network ([
5DN)) a This connects two 84Kb/S digital data (which can be voice or data) and a 113Kb/S signal channel (which can be used to transfer data when no signal is flowing) to a traditional telephone subscriber line. The two 64 Kb/S channels are separated by B1 channel and B2 channel, and the 16 Kb/S signal channel is separated by 11f from D channel.

(Problems to be Solved by 'i'i6151) 1-1 of the present invention is to provide a system for accommodating the above-mentioned 2B10 digital subscriber lines in an exchange.

[Child actor to solve problems]

The digital switching system of the present invention has means for identifying whether each subscriber has a circuit-switched call or a packet-switched call, means for converting the speed for each call in the case of a circuit-switched call, and means for converting input data in the case of a packet-switched call. Accumulate.

It has means for packetizing data and sending it out, and means for disassembling the packet data and outputting it as serial data in the case of a packet-switched call.

Therefore, regardless of whether the input call is a circuit-switched call or a packet-switched call, the same subscriber interface circuit can provide a highly flexible digital exchange in response to the service requests of the subscriber.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a digital exchange according to the present invention.

The telephone subscriber line is output to the digital subscriber line transmission circuit l via a transformer by a tip line T and a ring line R. The digital subscriber line transmission circuit 1 uses a Bing-Bong system or an echo canceller type, and B of the digital subscriber line 1-,
, B, , D channels are separated, and the B1 channel is connected to the B1 channel interface circuit 2. B? The channel is B2 channel interface circuit 3. D channel is D
The signal is input to the channel interface circuit 4.

These interface circuits 2, 3.4 are connected to a microprocessor 6, a program read-only memory (ROM) 7, and a read/write memory (RA) via a processor 5.
M) Combined with 8.

B. In the channel interface circuit 2, the signal from the digital subscriber line transmission circuit 1 is converted into a speed conversion circuit! ! A packet assembling circuit 13 is further connected to the 0 selection circuit 12 which is outputted to the digital communication path 9 via the selection circuit 12, and a gate for controlling selection of this selection circuit 12 is performed by an input/output control circuit 10. Also, the speed conversion mode, for example 8 Kb/S→E14Kb/S, IEiKb
/S→134Kb/S, 32Kb/S→84Kb/S,
The selection from 64 Kb/S to 84 Kb/S, etc. is performed by instructing the speed conversion circuit 11 by the input/output control circuit 10. Also, speed conversion circuit 1! The output is input to the microprocessor 6 via the serial interface circuit 14.

Conversely, the input from the digital communication path 9 is sent to the speed conversion circuit 15.
Data from the microprocessor 6 is input to the 0 selection circuit 15 via the serial data interface 17 to the selection circuit 1B and to the packet decomposition circuit 18, forming a data communication path for a packet switched call. The output B of the 0 selection circuit 1B (X14T) receives instructions from the input/output control circuit 1o and is the digital subscriber transmission circuit l.
is input to.

Next, the overall operation of this embodiment will be explained. Input B1
Whether the channel data B, (RCV) is a circuit switched call or a packet switched call is determined by the microprocessor 6 via the D channel interface circuit 4 according to D channel signal data.
will be notified. Through a predetermined program operation, the microprocessor 6 instructs to open the gate of the circuit-switched OS of the selection circuit 12 in the case of a circuit-switched call, and at the same time, the input/output control circuit 10 instructs the speed (for example, 84 in the case of a voice call).
Kb/S - 84Kb/S, 8Kb/5 (7) data na I" + 8 Kb/S → 84Kb/S),
The digital communication path 9 switches this 84 Kb/S data to a predetermined destination, and also instructs the selection circuit 12 to open the gate PS on the packet switching side if the call requests a packet switching service. The packet assembly circuit 13 is selected by the selection circuit 12. Input data is also input to the microprocessor 6 via the serial interface circuit 14. The microprocessor 6 stores this input data using a predetermined program and transfers it to the packet assembly circuit 13. The digital communication path 9 switches this data according to the destination.

The operation from the switching side to the subscriber side is similar; data from the digital communication path 9 is sent to the digital subscriber line transmission circuit l via the speed conversion circuit 15 in the case of a circuit-switched call, and is depacketized in the case of a packet-switched call. The circuit 18 disassembles the packet, the microprocessor 6 converts it into serial data, and the serial interface circuit 17 . The digital power j1 is sent to the personal line transmission circuit 1 via the selection circuit 16.

〔Effect of the invention〕

As described above, the present invention uses the D channel to identify whether a call is a packet-switched call or a circuit-switched call, converts the speed if the call is a circuit-switched call, and converts input and output serial data into packet assemblies for packet calls. By equipping each call of 28+D subscriber lines with a digital subscriber line, one digital subscriber can receive circuit-switched services for voice, circuit-switched data, and packet-switched services. It is flexible enough to provide services and can respond to the diversification of services! This has the effect of providing a digital exchange that can

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital exchange according to the present invention. 1...Digital subscriber line transmission circuit, 2...
...B, channel interface circuit, 3...
・B2 channel interface circuit, 4...
D channel interface circuit, 5...Brossee 2 Sabbath, 6...Microprocessor, 7...ROM, 8...RAM, 9... ...Digital Zhao Story. lO... Human output control circuit. 11.15... Speed conversion circuit. 12.18...Selection circuit, 13...Packet decomposition circuit. 14, 17... Serial interface circuit. z8・・・・・・・・・Packet disassembly circuit.

Claims (1)

[Claims] In a digital exchange that accommodates 2B+D digital subscriber lines, there is a means for identifying whether each subscriber is a circuit-switched call or a packet-switched call, a means for speed conversion for each call in the case of a circuit-switched call, and a means for converting the speed of each call for each subscriber, A digital exchange characterized in that it includes means for accumulating input data, packetizing and transmitting the data in the case of a call, and means for disassembling the packets and outputting them as serial data in the case of a packet-switched call.