JP3643628B2 - Line control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus capable of connecting an I ′ interface composed of a plurality of ISDN lines, and in particular, controls a plurality of ISDN communication lines by one call control information channel (D channel) of the plurality of ISDN lines. It is related with the apparatus to do.
[0002]
[Prior art]
The I 'interface is an interface between a digital network and a PHS public base station, and its structure is "TTC Standard Volume II Volume 4 User / Network Interface [User / Network Interface Mobile Communication Related] 1993 (1st Edition)" Published by: Telegraph and Telephone Technical Committee P243-P245.
[0003]
As shown in FIG. 3, this I ′ line is composed of a plurality of ISDN lines 2B + D and 2B × n (n is an integer).
A conventional line control apparatus capable of connecting an I ′ line will be described with reference to FIG.
401 is an I ′ line composed of a plurality of ISDN lines, 402 is a line connecting unit for physically connecting the I ′ line 401, and 403 is a D channel (call control information channel for performing call control from the line connecting unit 402 ), And assembles and disassembles the B channel (data channel) packet data and supplies a B channel information signal to a main control unit 405, which will be described later. An information channel control unit for assembling and disassembling channel packet data and supplying a B channel information signal to a main control unit 405, which will be described later. 405 is composed of a CPU or the like, and includes an information channel / D channel control unit 403 and an information channel control unit. The line controller is configured by a main control unit that receives information from 404 and performs predetermined control based on the information. There. In particular, the information channel / D channel control unit 403 connects the line 406 having the D channel, thereby simultaneously controlling the call control of the line 407 having only other information channels, thereby realizing D channel sharing. For example, when information is transmitted / received via the line 407 having no D channel, the D channel is extracted from the line 406 having the D channel via the information channel / D channel control unit 403, and after performing call control, the information Was sending and receiving.
[0004]
[Problems to be solved by the invention]
In the conventional line control apparatus, the line 406 having the D channel must be fixedly connected to the line connection unit 402 connected to the information channel / D channel control unit 403. For some reason, the line 406 has the D channel. When the line is connected to a different line connection part or when a failure occurs in the D channel, the I ′ line cannot be communicated.
[0005]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a line control device that operates normally regardless of which line connection unit a line having a D channel is connected to. .
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a line control apparatus including a plurality of line connection units for connecting I ′ lines composed of a plurality of ISDN lines, and the plurality of ISDN lines connected to the plurality of line connection units. A D channel control unit for detecting an ISDN line having a D channel from the ISDN line and extracting D channel information from the ISDN line having the D channel; and an information channel control unit for extracting packet data from the plurality of line connection units. And the I ′ line is controlled based on the D channel information extracted by the D channel controller.
[0007]
A second aspect of the present invention is the first aspect of the present invention, wherein the D channel control unit sets an ISDN line having a D channel depending on presence or absence of a layer 2 synchronization signal of the plurality of ISDN lines connected to the plurality of line connection units. It is characterized by detecting.
According to a third aspect of the present invention, in the first aspect, the D channel control unit detects an ISDN line having a D channel based on a result of link setting for the plurality of ISDN lines connected to the plurality of line connection units. It is characterized by.
[0008]
A fourth aspect of the present invention is the method according to the third aspect, wherein the D channel control unit performs link setting for the plurality of ISDN lines connected to the plurality of line connection units, and has a ISDN line having a response as a D channel. It is detected as an ISDN line.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the line control apparatus of the present invention will be described.
FIG. 1 is a functional block diagram showing an embodiment of the line control apparatus of the present invention. FIG. 2 and FIG. 3 are flowcharts showing an embodiment of the D channel line determination operation in the line control apparatus of the present invention.
[0010]
In FIG. 1, 101 is an I ′ line composed of a plurality of ISDN lines, 102 is a line connection unit for physically connecting the I ′ line 101, and 103 is a D that performs call control from the line connection unit 102. A D channel control unit for extracting a channel (call control information channel), and 104 a B channel information signal obtained by assembling and disassembling B channel (data channel) packet data from the line connection unit 102 to a main control unit 105 to be described later An information channel controller 105 to be supplied is composed of a CPU or the like, and receives information from the D channel controller 103 and the information channel controller 104, and a line controller is controlled by a main controller that performs predetermined control based on the information. It is configured. In the present embodiment, it is assumed that the I ′ line is composed of 2B + D and 2B. The information channel control unit 104 is provided with an echo canceller circuit (not shown), and cancels the voice on the B channel and processes only the packet data.
[0011]
With the above configuration, the D channel line determination operation of the D channel control unit 103 will be described with reference to FIG.
The D channel control unit 103 sequentially analyzes the D channel signals for the lines connected to the plurality of line connection units 102 in the order set in advance. In the present embodiment, it is assumed that the D channel signal of the connected ISDN line is analyzed in the order of the line connection unit 102A and the line connection unit 102B. Further, it is assumed that the ISDN line 106 connected to the line connection unit 102A is 2B + D and the ISDN line 107 connected to the line connection unit 102B is 2B.
[0012]
In S1, frame synchronization of the ISDN line 106 connected to the line connection unit 102A is performed, and the D channel signal is analyzed.
In S2, it is determined whether or not a flag that is a synchronization signal of layer 2 exists in the D channel analyzed in S1, and if a flag is detected, the process proceeds to S4 and corresponds to each line connection unit in advance. Information indicating flag detection is stored in the attached register. On the other hand, if the flag is not detected in S2, the process proceeds to S3, and information indicating that the flag could not be detected is stored in a register prepared in advance associated with each line connection unit. In the present embodiment, the process proceeds to S4.
[0013]
In S5, frame synchronization of the ISDN line 107 connected to the line connection unit 102B is performed, and the D channel signal is analyzed.
In S6, it is determined whether or not a flag that is a synchronization signal of layer 2 is present in the D channel analyzed in S5. If the flag is detected, the process proceeds to S8 and corresponds to each line connection unit in advance. Information indicating flag detection is stored in the attached register. On the other hand, if the flag is not detected in S6, the process proceeds to S7, and information indicating that the flag could not be detected is stored in a register prepared in advance associated with each line connection unit. In the present embodiment, the process proceeds to S7.
[0014]
In S9, it is determined whether or not the register associated with the line connection unit 102A stores information indicating that the flag has been detected, and if information indicating that the flag has been detected is stored, S10 Then, a layer 2 link setting request signal is transmitted to the ISDN line 106 connected to the line connection unit 102A, and the process proceeds to the next step. On the other hand, if information indicating that the flag is not detected is stored in S9, the process proceeds to S11.
[0015]
In S11, it is determined whether or not the register associated with the line connection unit 102B stores information indicating that the flag has been detected. If the information indicating that the flag has been detected is stored, S12 Then, a layer 2 link setting request signal is transmitted to the ISDN line 107 connected to the line connection unit 102B, and the process proceeds to the next step. On the other hand, if information indicating that the flag is not detected is stored in S11, the process proceeds to S13.
[0016]
In S13, when the response signal to the layer 2 link setting request signal transmitted in S10 is from the ISDN line 106 connected to the line connection unit 102A, the line having the D channel is established and the layer 2 link is established. In S14, information indicating that the D channel is valid is stored in a register prepared in advance in association with each line connection unit, and the process proceeds to the next step. On the other hand, if there is no response signal in S13, the process proceeds to the next step.
[0017]
In S15, if the response signal to the layer 2 link setting request signal transmitted in S12 is from the ISDN line 107 connected to the line connection unit 102B, the line having the D channel established through the layer 2 link. In S16, information indicating that the D channel is valid is stored in a register prepared in advance in association with each line connection unit, and the process proceeds to the next step. On the other hand, if there is no response signal in S15, the process proceeds to the next step.
[0018]
In S17, when information indicating that the D channel is valid is stored in a plurality of registers prepared corresponding to each line connection unit, that is, a plurality of lines (two lines in this embodiment). ) To the layer 2 link setting request signal, the layer 2 link is established, and it is determined that the plurality of lines have the D channel, the process proceeds to S18, and the upper layer further sets the D channel of each line. It is determined whether or not connection is possible, and in S19, the link on the line side that cannot be connected is disconnected. In S20, the flag cannot be detected in the register prepared in association with the line connection part that cannot be connected. Information indicating the effect is stored. In other words, since there cannot be two or more lines having the D channel in the I ′ line 101, when the lower layer cannot be determined, the line having the D channel is detected by the upper layer.
[0019]
In S17, when information indicating that the D channel is valid is stored in a plurality of registers prepared in association with each line connection unit, a line having the D channel is detected. As other processing, the process proceeds to S21, and the line connection unit 102B having the second priority order is set based on the preset priority order of the line connection units (in this embodiment, the order is 102A and 102B). In step S22, information indicating that the flag could not be detected is stored in a register prepared in association with the second priority line connection unit.
[0020]
Through the detection process as described above, the D channel control unit 103 extracts the D channel information from the line having the D channel based on the register corresponding to each line connection unit after detecting the line having the D channel, and detects the D channel information. The signal is supplied to the main control unit 105 via the signal line 108.
The main control unit 105 can extract D channel information regardless of which ISDN line of the I ′ line is connected to any line connection unit, and can manage information channel information corresponding to each line based on this D channel information. .
[0021]
As described above, in the present embodiment, the case where the I ′ line has two ISDN lines has been described. In that case, the line connection unit 102 (FIG. 1) is provided by the number of ISDN lines that the I ′ line has, and steps S1 to S8, S9 to S12, and S13 to S16 of the D channel detection processing flow (FIG. 2) are performed. If processing is performed on the line connection section provided, it is possible to cope with an I ′ line having a large number of lines.
[0022]
【The invention's effect】
In the first and second aspects, the D channel information can be extracted and the control based on the D channel information can be performed regardless of which line connection portion connects the plurality of ISDN lines of the I ′ line. Can be connected to the line control device without distinguishing between a line having a D and a line not having a D channel, and troubles due to an erroneous connection of the line, a failure of the D channel, or the like can be prevented.
[0023]
In the second and third aspects, in addition to the effects of the first and second aspects, a line having a D channel is detected by link setting by an upper layer. Even if detected, a line having a normal D channel can be detected.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing an embodiment of a line control apparatus of the present invention.
FIG. 2 is a flowchart showing an embodiment of D channel detection processing of the line control apparatus of the present invention.
FIG. 3 is a schematic diagram of an I ′ line.
FIG. 4 is a functional block diagram showing an embodiment of a conventional line control apparatus.
[Explanation of symbols]
101, 401 I 'line 102, 402 Line connection unit 103 D channel control unit 104, 404 Information channel control unit 105, 405 Main control unit 403 Information channel / D channel control unit

Claims (4)

In a line control apparatus provided with a plurality of line connection parts for connecting I 'lines composed of a plurality of ISDN lines,
A D channel control unit for detecting an ISDN line having a D channel from the plurality of ISDN lines connected to the plurality of line connection units, and extracting D channel information from the ISDN line having the D channel;
An information channel control unit that extracts packet data from the plurality of line connection units;
A line control apparatus for controlling the I ′ line based on D channel information extracted by the D channel control unit. In claim 1,
The line control apparatus, wherein the D channel control unit detects an ISDN line having a D channel according to presence or absence of a layer 2 synchronization signal of the plurality of ISDN lines connected to the plurality of line connection units. In claim 1,
The line control device, wherein the D channel control unit detects an ISDN line having a D channel based on a result of link setting for the plurality of ISDN lines connected to the plurality of line connection units. In claim 3,
The D channel control unit performs link setting for the plurality of ISDN lines connected to the plurality of line connection units, and detects an ISDN line having a response as an ISDN line having a D channel. apparatus.

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