KR950013837B1 - Multiplexer and control method of the network ternunation method - Google Patents

Abstract

The multipoint scheme is adopted by the network terminal equipment to increase the efficiency of line occupation in S-interface. The multiplexor comprises S-interface units(4A) for connecting subscriber's terminal, S-transceivers and U-transceivers for communicating data between microprocessor unit through D-bus, a switching matrix(10) for switching data between S-transceivers and U-transceivers through B-bus, and a microprocessor unit(11) for transmitting data between S-transceivers and U-transceivers through C-bus and for controlling the switching matrix.

Description

Multiplexer of network terminal device and its control method

1 is a block diagram of a conventional network terminal device (NTE).

2 is a block diagram of a network terminal device according to the present invention.

3 is a flowchart for explaining a D-channel contention control operation process in the present invention.

4 is a flowchart for explaining a control operation of a micro processing unit (MPU) in the present invention.

* Explanation of symbols for main parts of the drawings

1 ₁ , 1 ₂ ,.. 1 _n : S transmitter 2 ₁ , 2 ₂ ,.. 2 _n : U transceiver

4A: S interface 5A: U interface

10: switching matrix 11: micro processing unit (MPU)

NTEM: Multiplexer of Network Terminal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexer and a method of controlling the same for increasing the efficiency of using an ISDN subscriber line in a network termination equipment (hereinafter referred to as NTE).

In the conventional NTE, as shown in FIG. 1, the S transmitter 1 connected to the subscriber station through the S interface 4 and the U transmitter 2 connected to the S transmitter 1 and the microcontroller 3 are subscribers. It is connected to ISDN through the U interface (5).

In the conventional NTE configured as described above, the S transmitter 1 of the CCITT 430 standard controls the S interface 4, and the U receiver 2 of the ANSITI.6 standard controls the U interface 5 of the subscriber line. The subscriber information capacity at each interface is 2B + D (144 Kbps). However, since the electrical characteristics are different on the S interface 4 and the U interface 5 which is the subscriber line, they are converted to each other through the N-bus (NTE-bus).

That is, the signal is transmitted to the digital signal via the signal receiver S (1) sent by the subscriber to the U transceiver 2 via the N-bus, which is converted into an electrical signal of the U interface (5) and transmitted to the ISDN side.

On the other hand, the signal transmitted from ISDN is converted into a digital signal through the U transceiver (2) and input to the S transmitter (1) via the N-bus, which is converted into an electrical signal of the S interface (4) to the subscriber side. Is sent.

Here, the microcontroller 3 detects and monitors the S interface 4 and the subscriber line state displayed through the N-bus, and controls the operation (Activation & Deactivation) of each interface.

However, in the conventional NTE, one subscriber station has a transmission capacity of 2B + D. Since the B channel has a transmission rate of 64Kbps, it is used for voice or data, and the D channel has a transmission rate of 16Kbps for signaling. Used.

That is, one subscriber has the same effect as having two terminals (2B), but when the channel is not used, the subscriber line is in the channel idle state (Idle), so there is a problem that the utilization efficiency of the line is deteriorated. .

Therefore, an object of the present invention is to adopt a multipoint method on the S interface to increase the efficiency of the use of the S interface line, while at the same time the switching operation in the NTE multiplexer to reduce the no-call state of the subscriber line to more subscriber lines To accept subscribers.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 shows a block diagram of a network terminal multiplexer (NTEM) according to the present invention, which includes a plurality of S interfaces 4A for connecting a plurality of subscriber stations and a microprocessing unit 11 through a D bus. A plurality of S transmitters (1 ₁ , 1 ₂ ,... 1 _n ) and U transmitters (2 ₁ , 2 ₂ ,... 2 _n ) that exchange messages with the S transmitters (1 ₁ , 1 ₂ , ... 2 _n) and U transceivers _{(2 1, 2 2, ...} 2 n and the switching matrix 10 to switch the transmission and reception of data via the D bus, the S transceiver _{(1 1, 1 2, ...} 1 n with)) and It consists of a micro-processing unit 11 which exchanges messages with the U transmitters 2 ₁ , 2 ₂ ,... 2 _n and controls the switching operation of the switching matrix 10 via the C bus. Reference numeral 5A is a U interface, ISDN is a comprehensive telecommunications network.

In the control method related to the multiplexer of the network terminal apparatus according to the present invention configured as shown in FIGS. 3 and 4, the terminal detects whether the D channel is empty and is empty. Multipoint process that detects whether a collision occurs by comparing the echo bits and abandons the use of the D channel if a collision occurs, and occupies the D channel if a collision does not occur, and in the waiting state for message transmission through the D channel. The processing unit 11 detects which message is being input and is inputted, and again detects whether a call request signal is input from the ISDN, detects whether the call is in a released state, and if so, blocks and releases the B bus line. If it is a detection state After switching the B bus, the received message is written to the S transmitter. If the call request signal is not detected from the ISDN, it detects whether the call is in a disconnected state. If it is in the disconnected state, it blocks the B bus line. If the detection of the authorization is detected, the switching is performed by switching the B bus, writing the received message to the corresponding U transceiver, and returning to the D channel message transmission standby state.

The operation and effect of the present invention made as described above will be described with reference to FIGS. 2 to 4.

First, the branch operation process is described. One S-interface has a transmission capacity of 2B + D. Since one B-channel can accommodate one telephone or one data terminal, 2B has two dedicated channels. That means you can.

In general, up to eight terminals can share two B-channels, but as the number of terminals increases, the transmission state becomes unstable. In addition, one D channel exists for a signal, and when two terminals simultaneously access the D channel, a collision occurs, and thus a driving mechanism for controlling the D channel is required. That is, as shown in FIG. 3, the E bit is a D channel echo bit, and the D channel bit sent from the terminal is looped back. At this time, the terminal detects whether the d channel is empty and occupies the D channel if it is empty.

If the D-channel bit and echo bit do not match during the D-channel use, a collision occurs, and the use of the D-channel is immediately abandoned.

Referring to the next switching operation of the network damnal Xi multiplexer, S interface, as shown in FIG. 4 _{(1 1, 1 2, ...} 1 n) request originating through when first D-channel to request the calling any subscriber on the Will send a message.

The outgoing request message is input to the microprocessing unit 11 via the S transmitters 2 ₁ , 2 ₂ ,... 2 _n , so that the microprocessing unit 11 has a U channel which is currently idle. It selects the transceiver and writes this message through the D bus and switches the B bus, the B channel path between the subscriber and the subscriber line.

At this time, the D-channel message written to the selected U transceiver is transmitted to the ISDN side.

Afterwards, all messages transmitted and received between the corresponding S transmitter and the selected U transmitter that sent the outgoing request message go through the microprocessing unit 11, so that the microprocessing unit 11 transmits the call properly and whether the outgoing request is released. It is determined whether or not it is switched on or off.

In the case of an incoming call, a call request signal is transmitted from the ISDN side to a specific subscriber through the D channel. The message is input to the microprocessing unit 11 through the D bus via the U transceiver.

At this time, the terminating number type of the network terminal multiplexer (NTEM) has a representative telephone number and a sub address. All subscriber lines of n NTEMs have the same representative telephone number, and the subscriber terminals are distinguished by sub addresses.

Accordingly, the microprocessing unit 11 reads the third address of the incoming message, transfers the message to the S transmitter connected to the subscriber station, and switches the B channel. Here, the C bus is used to control the operation of the switching matrix 10 when the D-channel data transmission and initialization operations between the S transmitter and the U transceiver and the micro processing unit 11 and the B bus are to be switched. The processing in the case of incoming and outgoing calls is similar to the flowchart of FIG.

As described above, the present invention can increase the use efficiency of the S interface line by adopting the branching method on the S interface in the network terminal device, and also the switching of the subscriber line by the switching operation in the NTE multiplexer ( It is possible to reduce the idle state, so it can accommodate more subscribers even with fewer subscriber lines.

Claims (2)

A plurality of S interfaces 4A allowing a plurality of subscriber stations to be connected, and a plurality of S transmitters 1 ₁ , 1 ₂ ,..., 1 _n and U for exchanging messages with the microprocessing unit 11 via the D bus. transceivers _{(2 1, 2 2, ...} 2 n) , and the S transceiver via the B bus _{(1 1, 1 2, ...} 1 n) and transceivers _{(2 1, 2 2, ...} 2 n) switching the transmission and reception of data between the matrix (10), the S transceiver via the D bus _{(1 1, 2 2, ...} 1 n) and U transceivers _{(2 1, 2 2, ...} 2 n) and at the same time the exchange of messages in said through C bus A multiplexer of a network terminal device, characterized in that it comprises a micro processing unit (11) for controlling the switching operation of the switching matrix (10). If the terminal detects whether the channel D is empty and if it is empty, it transmits the D channel signal and compares whether the D channel bit and the echo bit match and detects whether a collision occurs. The multipoint process occupying the channel and the microprocessing unit 11 detects which message is being input in the message sending standby state through the D channel, and detects whether a call request signal is input from the ISDN if it is input. In case of detection, it detects whether the call is released or not, and if it is in the off state, it blocks the B bus line. If not, it detects the incoming call. If the call request signal is not detected from the ISDN, Blocks the B-bus signal if it is in the off state by detecting the acknowledgment.If it is not in the released state, it detects whether it is an incoming call request state.If it is in the detected state, it switches the B-bus and writes the received message to the corresponding U-transmitter. A control method of a network terminal device, characterized in that to perform a switching process to return to the state.