JPH0744708B2 - Simple adapter for multiplexing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an ISDN (Integrated Services Digital Network).
k: Comprehensive service digital network) Used as a multiplexing adapter for the basic subscriber access system of terminals. The present invention relates to a multiplexing adapter for connecting a plurality of ISDN terminals to a network terminating device via an S interface.

〔Overview〕

According to the present invention, in a simple multiplexing adapter for connecting a plurality of ISDN terminals to a network terminating device, an S interface bus on the network terminating device side and a plurality of S interface buses on the ISDN terminal side are terminated by a layer 1 terminating circuit to form a B channel. It is separated into D channel, and data is transferred from the network side to the terminal side by broadcasting for the D channel, contention control is performed from the terminal side and data is transferred to the network side, and the B channel is detected from the D channel. By selecting and connecting the network side and terminal side based on call control information, it is possible to easily add ISDN terminals.

[Conventional technology]

FIG. 3 is a diagram showing a conventional in-house wiring configuration of a basic subscriber access system. In FIG. 3, 22 is a network terminating device (hereinafter referred to as NT), 32-34 are terminating resistors and 42-.
44 indicates an ISDN terminal.

Conventionally, in the home wiring form of the ISDN basic subscriber access system, there is a point where only one pair of transmitter and receiver exists at each end point of the cable as shown in Fig. 3 (a).
A point configuration, or a point-multipoint configuration with a passive bus that allows up to eight ISDN terminals (hereinafter referred to as TE) to be connected to any point over the entire length of one wiring as shown in FIG. 3 (b). The point where the passive bus is extended by arranging the TE connection points as shown in Fig. 3 (c) collectively at the far end of the line from the network terminator.
Three in-house wiring configurations with a multipoint configuration were considered.

[Problems to be solved by the invention]

However, in such a conventional ISDN basic subscriber access system, the maximum number of TEs is limited in order to guarantee the electrical characteristics, even though a maximum of 127 TEs can be logically identified. (CCITT Recommendation I.430 states that the maximum number of TEs is 8 in the case of point / multipoint configuration with passive bus.) However, there is a drawback that more TEs cannot be added.

The present invention solves the above-mentioned drawbacks, and an object of the present invention is to provide a multiplexing simple adapter which can easily add an ISDN terminal.

[Means for solving problems]

The present invention is a multiplexing adapter for connecting a network terminating device and a plurality of ISDN terminals, which multiplexes and expands an S interface bus which is a basic interface between the network terminating device and the ISDN terminal. In an ISDN terminal multiplexing adapter that multiplexes a plurality of ISDN terminals to a network terminating device at a layer 1 level, the network terminating device is connected to the network terminating device via an S interface bus to realize the layer 1 basic interface to realize a B channel and a D channel. And a plurality of terminal side layer 1 termination circuits that are connected to the plurality of ISDN terminals respectively via the S interface bus to realize the layer 1 basic interface and separate the B channel and the D channel. It is inserted between the circuit and the layer 1 termination circuit on both sides, and the layer 1 start-up input from one side or A layer 1 activation control circuit that gives an activation instruction that is a start or stop instruction to the other on the basis of layer 1 activation information regarding stop, and a D channel signal of the network side layer 1 termination circuit, and the plurality of terminal side layer 1 termination circuits. And a transfer control means for giving D channel signals of one terminal side layer termination circuit to the network side layer 1 termination circuit when the D channel signals of the plurality of terminal side layer 1 termination circuits compete with each other by broadcasting. One of the B channels of the plurality of ISDN terminals inserted between the layer 1 termination circuits on both sides.
A B channel switching circuit that selects a channel and connects to the B channel on the network side, and a D channel that detects the call control signal of the D channel signal output by the layer 1 termination circuits on both sides and outputs the B channel connection information. A signal monitor circuit and a B channel switching control circuit for giving a selection control signal to the B channel switching circuit based on connection information of the B channel output from the D channel signal monitoring circuit are provided.

[Action]

The layer 1 activation control circuit inserted between the layer 1 termination circuits on the network side and the terminal side gives an activation instruction to the other layer 1 termination circuit based on the layer 1 activation information input from one layer 1 termination circuit. . This activation instruction is activated by the INFO signal /
It means an operation for instructing the other layer 1 termination circuit to send out an INFO signal indicating a start / stop request based on the stop request. When the transfer control means gives the D channel signal of the network side layer 1 termination circuit to the terminal side layer 1 termination circuit by broadcasting respectively, and when the D channel signals of a plurality of terminal side layer 1 termination circuits compete, one terminal side layer termination The D channel signal of the circuit is given to the network side layer 1 termination circuit. The D-channel signal monitor circuit detects the call control signal of the D-channel signal output from the layer 1 termination circuits on both sides, and B
Output the connection information of the channel. B based on the connection information of the B channel output from the D channel signal monitor circuit
The channel switching control circuit outputs a B channel selection control signal. In accordance with this selection control signal, the B channel switching circuit selects the B channel connection of the layer 1 termination circuits on both sides. With the above operation, multiple ISDN terminals (8 or more)
It is possible to easily add layers 2 and 3 to a subscriber line without terminating them.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. First
FIG. 1 is a block diagram of a multiplexing simple adapter according to an embodiment of the present invention. In FIG. 1, the simple multiplexing adapter includes a network side layer 1 termination circuit 1 connected to a network termination device (not shown) via an S interface bus 100, and a plurality of ISs (not shown).
A layer 1 terminal circuit 11 ₁ to 11 _3, respectively via the S interface bus 119 _{1-119 3} to DN terminal connected terminal side,
Inserted between the layer 1 termination circuits 1 and 11 _{1 to} 11 ₃ on both sides,
A layer 1 activation control circuit 8 for giving a layer 1 control signal for instructing activation to the other on the basis of layer 1 activation information inputted from one side, and a D channel signal of a layer 1 termination circuit 1 on the network side to a layer 1 on the terminal side.
Giving each terminating circuit 11 ₁ to 11 _3, a transfer control means for giving to the layer 1 terminal circuit 1 of the network side in conflict control D channel signal layer 1 termination circuit 11 ₁ to 11 ₃ of the terminal side, both sides of the layer B channel switching circuit 5 which is inserted between 1 termination circuits 1 and 11 _{1 to} 11 ₃ to select B channel connection, and D channel signals output from layer 1 termination circuits 1 and 11 _{1 to} 11 _{3 on} both sides are detected. And a B channel switching control circuit 6 for giving a selection control signal to the B channel switching circuit 5 based on the call control signal detected by the D channel signal monitoring circuit 2.

The transfer control means is connected to the layer 1 termination circuit 1 and controls the transfer of the D channel signal on the network side, the D channel signal transfer control circuit 3, the D channel signal transfer control circuit 3 and the layer 1
The outputs of the D channel signal transfer control circuits 7 _{1 to} 7 ₃ on the terminal side inserted between the terminal circuits 11 _{1 to} 11 ₃ and the D channel signal transfer control circuits 7 _{1 to} 7 ₃ are competitively controlled to control the D channel. The contention control circuit 4 is provided to the signal control circuit 3.

Here, the layer 1 termination circuit 1 and the layer 1 termination circuit 11 ₁
To 11 _3, realizes the basic interface layer 1 specification as specified in CCITT Recommendation I.430 about ISDN, it separates the B channel and D channel and extracts Layer 1 activation information.

This layer 1 activation information indicates the start / stop request by the INFO signal specified in the recommendation, and the activate instruction is the start / stop by the INFO signal input from one side.
Based on the stop request, it means an operation for instructing the other layer 1 termination circuit to send out an INFO signal which means a start / stop request.

Further, the D channel signal has a frame structure, and the D channel signal transfer control circuits 7 _{1 to} 7 ₃ receive the D channel signal in frame units and hold it internally, and request the use of the D channel signal bus 106. Competing control circuit 4
D from the D-channel signal bus 100
The data is written in the channel signal transfer control circuit 3.

Further, the B-channel switching circuit 5 monitors the call control information in the D-channel signal by the D-channel signal monitor circuit 2 and, based on the call control information, controls a plurality of B-channel switching control circuits 6. It has a function of selecting one of the B channels of the ISDN terminal and connecting to the B channel on the network side.

The operation of the simple multiplexing adapter having such a configuration will be described. In FIG. 1, the signal received from the NT side (not shown) is terminated by the layer 1 termination circuit 1, and the B ₁ channel 101 and B ₁
It is separated into _two channels 102 and D channels 103 and input to the B channel switching circuit 5 and the D channel signal transfer control circuit 3. The D channel signal from NT is transferred in broadcast format through the TE side D channel signal transfer control circuit 7 _{1 to} 7 ₃ to the TE side layer 1 termination circuit 11 _{1 to} 11 ₃ and multiplexed with the B channel signal. It is sent to the S interface buses 119 ₁ to 119 ₃ .

Signal from the S interface bus 119 _{1-119 3} TE side conversely, are terminated by the layer 1 termination circuit 11 ₁ to 11 _3. Therefore separated D channel signal, via the D channel signal transfer control circuit 7 _{1-7 3} TE side, contention control is performed in contention control circuit 4. After that, it is multiplexed with the B channel signal in the layer 1 termination circuit 1 via the D channel signal transfer control circuit 3 on the NT side and sent to the S interface bus 100.

Regarding the layer 1 activation request from the NT side, the layer 1 termination circuit 1 detects it, the layer 1 activation control circuit 8 is driven by the layer 1 control signal 104, and the TE side layer 1 termination circuits 11 _{1 to} 11 ₃ perform TE. All layers 1 of are activated.

Similarly with respect to the layer 1 activation request from the TE side, it is detected by any of the layer 1 termination circuit 11 ₁ to 11 ₃ of the TE side, all TE and all layer 1 termination circuit is activated by the layer 1 activation control circuit 8 Layer 1 of all NT
Will be activated.

For the B channel, the D channel signal monitor circuit 2
The call control information for the B channel in the D channel signals on the NT side and the TE side is monitored, and the B channel switching control circuit 6 is driven. B channel switching circuit 5 is controlled by the B channel switching control circuit 6, TE side B ₁ channel 107 _11, 10
7 ₂₁ or 107 ₃₁ is connected to NT side B ₁ channel 101 _1, and TE side B ₂ channel is connected to either 107 ₁₂ , 107 ₂₂ or 107 ₃₂ and NT side B ₂ channel 101 _2. To do.

FIG. 2 is a diagram showing an in-house wiring configuration of a basic subscriber access system including the simple multiplexing adapter of the present invention. Second
In the figure, an S interface bus 121 ₂ to which TEs 41 ₃ and 41 ₄ are connected, an S interface bus 121 ₃ to which TEs 41 _{5 to} 41 ₇ are connected, and an S interface to which TEs 41 ₈ and 41 ₉ are connected by a simple multiplexing adapter 10 bus 121 ₄ and TE41 _1, 41 ₂ is S interface bus 121 ₁ is connected, it is independent of the physical but are S interface bus equivalent to one logically.

〔The invention's effect〕

As described above, the present invention can construct an S interface bus that is logically equivalent to one S interface bus and is physically independent, and branches the S interface bus without terminating Layer 2 and Layer 3. It also has the excellent effect of being able to expand and easily add ISDN terminals.

[Brief description of drawings]

FIG. 1 is a block diagram of a multiplexing simple adapter according to an embodiment of the present invention. FIG. 2 is a diagram showing a home wiring configuration of a basic subscriber access system including the simple multiplexing adapter of the present invention. FIG. 3 is a diagram showing a conventional in-house wiring configuration of a basic subscriber access system. 1, 11 _{1 to} 11 ₃ ... Layer 1 termination circuit, 2 ... D channel signal monitor circuit, 3, 71 _{1 to} 7 ₃ ... D channel signal transfer control circuit, 4 ... competition control circuit, 5 ... B Channel switching circuit, 6 ... B channel switching control circuit, 8 ... Layer 1 activation control circuit, 10 ... Multiplexing simple adapter, 21
~24 ...... NT (network termination equipment), 31 _{1-31 8,} 32 _1, 32 _2, 3
3 ₁ , 33 ₂ , 34 ₁ , 34 ₂ ...... Terminator, 41 _{1 to} 41 ₉ , 42, 43 ₁ ~
_{43 3, 44 1, 44 2} ...... TE (ISDN terminal), 100,119 _{1-119 3,}
121 _{1 to} 121 ₄ ...... S interface bus, 101 ₁ , 107 ₁₁ , 1
07 ₂₁ , 107 ₃₁ ...... B ₁ channel, 101 ₂ , 107 ₁₂ , 107 ₂₂ , 107
₃₂ …… B ₂ channel, 103, 109 ₁ , 109 ₃ …… D channel, 1
04, 116 _{1 to} 116 ₃ ... Layer 1 control signal, 105, 106 ... D
Channel signal bus, 202-204 ... Wiring in house.

Claims (1)

[Claims] 1. A multiplexing adapter for connecting a network terminating device and a plurality of ISDN terminals, wherein the multiplexing adapter branches and expands an S interface bus which is a basic interface between the network terminating device and the ISDN terminal. In the simple multiplexing adapter for multiplexing a plurality of ISDN terminals at the layer 1 level to the network terminating device, the network terminating device is connected to the network terminating device via the S interface bus to realize the layer 1 basic interface to realize the B channel and the D channel. A network side layer 1 terminating circuit (1) for separating the network side and a plurality of terminals for respectively connecting the plurality of ISDN terminals via the S interface bus to realize the layer 1 basic interface and separate the B channel and the D channel. a layer 1 terminal circuit (11 ₁ to 11 _3), is inserted between the opposite sides of the layer 1 termination circuit, inputs from one A layer 1 activation control circuit (8) which gives an activation instruction which is an activation or termination instruction to the other based on the layer 1 activation information relating to the activation or deactivation of the ear 1, and the D channel signal of the network side layer 1 termination circuit It is given to a plurality of terminal side layer 1 termination circuits by broadcasting,
Transfer control means (3, 4, 7) for giving D channel signals of one terminal side layer termination circuit to the network side layer 1 termination circuit when the D channel signals of the plurality of terminal side layer 1 termination circuits compete. , Inserted between the layer 1 termination circuits on both sides of the above
B channel switching circuit for selecting one of the B channels of the ISDN terminal and connecting to the B channel on the network side (5)
And a D channel signal monitor circuit (2) for detecting a call control signal of the D channel signal output from the layer 1 termination circuits on both sides and outputting connection information of the B channel, and an output of this D channel signal monitor circuit. And a B-channel switching control circuit (6) for supplying a selection control signal to the B-channel switching circuit based on B-channel connection information.