JP2000138768A - Forced line connecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a channel for a security terminal to connect to a monitoring center, while using all B channels at a customer home terminal. SOLUTION: This forced line connecting device 18 is provided between an ISDN exchange 13 and a customer home DSU 14 and a security terminal 20 is connected to the device 18. When the terminal 20 detects emergency and while customer home terminals 15a and 15b use the whole channels, the main control part 18e of the device 18 interrupts an RR monitor frame in the process of being exchanged halfway, logically releases one of the B channels and establishes communication between the terminal 20 and a monitoring center 10. The part 18e also logically releases one of the B channels by respectively transmitting a disconnection message to the customer home terminals and the exchange 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a forced line connection device,
In particular, the present invention relates to a device for forcibly establishing a connection with an emergency terminal such as a security terminal even when all B channels of an ISDN subscriber line are in use.

[0002]

2. Description of the Related Art Conventionally, the occurrence of an emergency such as a fire or an abnormal situation such as an intruder has been detected, and an emergency or abnormal state (hereinafter collectively referred to as an emergency) is sent to a monitoring center via an ISDN line. Security devices for reporting have been put into practical use. When such a security device detects an emergency, it automatically sends a call setup message to the monitoring center,
After the connection with the monitoring center is established, information on the detected emergency is transmitted to the monitoring center.

However, when the security device detects an emergency, it transmits a call setting message to the monitoring center if the subscriber line of the ISDN line is already in use to establish communication with the monitoring center. If it is not possible to do so and it is necessary to wait until a line becomes available, a problem arises in that it is not possible to respond quickly to an emergency. The basic interface of ISDN includes two B channels for transmitting user information, and
It is possible to use two or more terminals simultaneously on one subscriber line. Therefore, although the number of terminals connected to an ISDN line such as a telephone, a facsimile, a personal computer, etc. is increasing although the number of two B channels being used at the same time is generally small, all the B lines of the subscriber line are in use. It is possible that channels are busy at the same time.

[0004] FIG. 6 shows a diagram for establishing communication with a monitoring center when a security terminal detects an emergency when all two B channels are in use on a subscriber line of the ISDN line. One method is shown.

[0005] In the figure, a monitoring center 10 is connected to a DSU 14 installed in a user's home via an ISDN exchange 12. A security terminal, a telephone, and a facsimile are connected to a home bus extending from the DSU 14 via a relay 16a in the line disconnecting device 16. If the security terminal detects an emergency while the telephone and the facsimile are using the line using the two B channels (B1 and B2), the line disconnecting device 16 triggers an emergency signal from the security terminal as a trigger. 16a is operated to forcibly disconnect the S / T point of the home bus (layer 1 level disconnection). Thereafter, a call is made again from the security terminal to establish communication with the monitoring center.

[0006]

However, in the above-mentioned conventional technique, all the lines are forcibly disconnected, so that all the terminals in use become unavailable. There is a problem that both B channels are disconnected even though only one B channel is required among the B channels).
While communicating with the monitoring center using one B channel, the other B channel and D channel become vacant and the IS
There is also a problem that the use efficiency of the DN line is reduced.

In many cases, the monitoring center confirms that the security terminal is operating normally by performing D-channel packet communication with the security terminal. If the line is physically disconnected,
There has been a problem that the D-channel packet communication of such a security terminal is also disconnected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a security terminal which detects an emergency while all B channels of an ISDN line are in use. It is an object of the present invention to provide a forced line connection device that can quickly establish communication with a monitoring center and minimize the influence on other terminals in a user's house.

[0009]

Means for Solving the Problems In order to achieve the above object, a first invention is to forcibly establish communication with an emergency terminal by releasing communication between a home terminal connected to a home DSU and an ISDN exchange. A line connection device, comprising line connection means connected between the ISDN exchange and the home DSU, wherein the emergency terminal is connected to the line connection means without passing through the home DSU; Means for releasing, when the in-home terminal is using all the B channels of the subscriber line of the ISDN line, any of the B channels in use and establishing communication between the emergency terminal and the ISDN exchange; It is characterized by the following. Rather than physically disconnecting the line in use at the layer 1 level as in the prior art, only one of the B channels is logically released at the layer 2 level (data link), which is used for emergency terminals. Of B
Channels can be quickly secured, and the effect on in-home terminals using other B channels can be eliminated.

[0010] In a second aspect based on the first aspect, the line connection means comprises: the home terminal and the ISDN.
It is characterized in that one of the B channels is released by blocking the RR monitoring frame transmitted to and received from the exchange. By intercepting the monitoring frame of the RR (receivable) at the layer 2 level, the ISDN exchange can switch the RR from the home terminal.
Cannot be received, and the home terminal cannot receive the RR from the ISDN exchange, and the corresponding B channel is logically released.

[0011] In a third aspect based on the first aspect, the line connection means comprises the home terminal and the ISD.
One of the B channels is released by transmitting a disconnection message to the N exchange. By transmitting the disconnection message to the home terminal and the ISDN exchange by using the layer 2 level information transfer frame (I frame), the home terminal regards the disconnection message as being transmitted from the ISDN exchange, and the ISDN exchange transmits the disconnection message from the home terminal. Is transmitted and the release processing is executed (the ISDN exchange deems that it is communicating with the home terminal despite actually communicating with the line connection means,
The home terminal is considered to be communicating with the ISDN exchange although it is actually communicating with the line connection means), and can quickly disconnect any B channel.

In a fourth aspect based on the first to third aspects, the line connection means includes a first communication interface unit connected to the ISDN exchange,
A second communication interface unit connected to the SU, a terminal interface unit to which the emergency terminal is connected, and a connection between the first communication interface unit and the second communication interface unit; A transmission control unit connected between the first communication interface unit and the second communication interface unit for controlling a signal to the ISDN exchange; and a reception control unit and a transmission unit. A main control unit for releasing any of the B channels in use by controlling the control unit.

According to a fifth aspect of the present invention, there is provided a forced line connection device for releasing communication between a home terminal connected to a home DSU and an ISDN exchange and connecting an emergency terminal.
N switching equipment and the in-home DSU having line connection means connected, the emergency terminal is connected to the ISDN line via the line connection means without via the in-home DSU, the line connection means, The emergency terminal is the ISDN
A relay means for disconnecting the home DSU and the ISDN exchange is provided between a point connected to a line and the home DSU. Even when the connection between the home terminal and the ISDN exchange is physically disconnected as in the prior art, the point that the emergency terminal is connected to the ISDN line and the home DS
By disconnecting from the U, that is, downstream of the point where the emergency terminal is connected, the physical connection between the security terminal and the ISDN exchange (and the monitoring center connected to this ISDN exchange) can be maintained. , Can quickly establish a logical link with the ISDN exchange.

In a sixth aspect based on the fifth aspect, the line connection means comprises: a first communication interface unit connected to the ISDN exchange;
And a second communication interface unit provided with the relay means, a terminal interface unit to which the emergency terminal is connected, and a second communication interface unit connected between the first communication interface unit and the second communication interface unit. ,
A reception control unit that controls a signal from the ISDN exchange; a transmission control unit that is connected between the first communication interface unit and the second communication interface unit and controls a signal to the ISDN exchange; In addition to controlling a control unit and a transmission control unit, a main control unit that operates the relay unit to disconnect the home DSU from the ISDN exchange is provided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In this specification, “disconnection” means physical line disconnection at the layer 1 level.
“Release” means a logical disconnection (physically connected) at the layer 2 level.

<First Embodiment> FIG. 1 is a conceptual diagram of a system according to the present embodiment. Monitoring center 10
Are connected to the forced line connection device 18 via the ISDN exchange 12. The forced line connection device 18 is connected between the ISDN exchange 12 and the in-home DSU 14, that is, at the point U.
Is connected. A terminal 15a (telephone or the like) and a terminal 15b (facsimile or the like)
Is connected.

The forced line connection device 18 includes a first communication interface (I / F) 18a, a second interface 18b, a reception control unit 18c, a transmission control unit 18d, a main control unit 18e, and a terminal interface 18f. It is configured.

The first communication interface 18a
Terminates the subscriber line to the SDN exchange 12, and
At the time of downlink reception from the SDN exchange 12, it converts the 2-wire ping-pong transmission method to the 4-wire transmission / reception independent method and supplies the reception data to the reception control unit 18c. Also, the transmission control unit 1
At the time of uplink reception from 8d, the transmission is converted from the 4-wire independent transmission / reception independent transmission system to the 2-wire ping-pong transmission system and transmitted. Here, the two-wire ping-pong system uses the same two-wire transmission line for both transmission and reception, and switches the transmission direction between the upward and downward directions at regular time intervals, and performs bidirectional transmission on a pair of metallic cables. The 4-wire independent transmission / reception independent transmission method is a method for independently implementing digital transmission through a pair of transmission paths dedicated to the up direction and a pair of transmission paths dedicated to the down direction.

The second communication interface 18b converts the two-wire ping-pong transmission method to the four-wire independent transmission / reception transmission method and supplies it to the transmission control unit 18d when receiving the signal from the home DSU 14 in the upward direction. Also, at the time of downlink reception from the reception control unit 18c, conversion is performed from the 4-wire independent transmission / reception independent transmission system to the 2-wire ping-pong transmission system. Therefore, from the viewpoint of the in-home DSU 14, it is as if the forced line connection device 18 does not exist and it is connected to a normal U point.

When receiving a signal from the first communication interface 18a, the reception control unit 18c extracts a D channel from a layer 1 level data frame and converts it into a layer 2 level frame. Layer 2 level frames are generally LAPD (Link Access Procedure on the D
-channel), and is composed of an address section including SAPI and TEI, a control section, an information section, and the like. Note that S
The API is a receiving point for services provided by the layer 2 level,
TEI indicates an identifier of each terminal. Also, LAPD
Includes an information transfer frame and a monitor frame. The information transfer frame is used to transfer information at the layer 3 level, and the monitor frame includes RR (receivable), RNR
(Reception not possible), used to transmit REJ (retransmission request).

The transmission control section 18d converts the data transmitted from the main control section 18e into a layer 2 level frame, further converts it into a layer 1 data frame and supplies it to the upstream (first communication interface 18a). .

The main control section 18e supplies the data received from the reception control section 18c to the security terminal 20 via the terminal interface 18f, and transmits the data transmitted from the security terminal 20 via the terminal interface 18f to the transmission control section. 18d. The main control unit 18e
When receiving data (emergency call) from the security terminal 20 in a state where both the home terminals 15a and 15b are communicating and there is no vacancy in the B channel, the following process is performed to forcibly open one B channel. It is logically released and communication between the security terminal 20 and the monitoring center 10 is established.

FIG. 2 schematically shows a forced line release process executed at the layer 2 level of the forced line connection device 18. While the home terminals 15a and 15b are connected via the exchange 12, the D-channel is used periodically (one for ten seconds).
RR (receivable) monitoring frame at the layer 2 level is exchanged between the terminal and the exchange.
And confirms the receiving state of the other party to transmit and receive data.

In this state, when the security terminal 20 detects an emergency and transmits it to the main control unit 18e, the main control unit 18e requests the exchange 12 to connect via the transmission control unit 18d. The exchange 12 returns a message indicating that there is no free space because all the channels are being used by other terminals. When this message is received, the main controller 18e sends the first communication to the reception controller 18c. Interface 18
a, and issues a command to stop transmitting the RR of either the B1 or B2 channel (ie, the RR from the exchange 12) to the second communication interface 18b. Communication interface 1
8b from the channel B1 or the channel B2 (the channel that issued the command to stop transmitting the RR to the second communication interface 18b) (that is, the home D
RR from the SU 14 to the first communication interface 1
8a is instructed to stop transmitting.

It should be noted that the R of either channel B1 or B2
To stop the R transmission, specifically, the value of TEI is monitored. For example, the home terminal 15a targets the RR of the B1 channel when the TEI = 0 and the home terminal 15b targets the RR of the B2 channel when the TEI = 1. When TEI = 0
RR may be processed to stop the transmission.
As a result, if the home terminal 15a uses the B1 channel and the home terminal 15b uses the B2, and the reception control unit 18c and the transmission control unit 18d stop transmitting the RR of the B1 channel, the home terminal 15a sends the RR to the home terminal 15a. Is not transmitted to the exchange 12, and the RR from the home terminal 15a is not transmitted to the exchange 12, so that the home terminal 15a and the exchange 1 are not transmitted.
2 is released, and the main controller 18e releases the released B
Communication between the security terminal 20 and the monitoring center 10 can be established using one channel.

As described above, in the present embodiment, either channel is logically released by prohibiting the transmission of RR of either channel B1 or B2, and one empty channel for the security terminal 20 can be secured. Therefore, communication between all the home terminals is not cut off as in the related art, and any terminal can still perform communication using the ISDN line, and the influence on the home terminal can be minimized. .

Although the B1 channel is released in the above example, the B2 channel can be released in a similar manner, and it is possible to arbitrarily determine which of the B1 and B2 channels is released. Of course, when an emergency situation is detected by the security terminal 20 while both the B1 and B2 channels are in use, it is also desirable that the user decide in advance which channel to release, B1 or B2.

FIG. 3 schematically shows another forced line release process executed at the layer 3 level of the forced line connection device 18. At some point during the exchange of the monitoring frame RR between the home terminals 15a, 15b and the exchange 12, the main control unit 18e sends a B signal to the reception control unit 18c.
A command for transmitting a disconnection message (layer 3 level) to an information transfer frame of one of the channels 1, 1 and B2 and transmitting it to a home terminal (for example, the home terminal 15a) via the second communication interface 18b is issued. Also, the transmission control unit 18
Also for d, a command to put a disconnection message (layer 3 level) on the information transfer frame of layer 2 level and transmit it to the exchange 12 via the first communication interface 18a is issued.

From the home terminal (for example, the home terminal 15a), as described above, it appears as if the forced line connection device 18 does not exist.
The disconnection message transmitted from e is also determined to have been transmitted from the communicating party via the exchange 12, and a release request is transmitted in response to the disconnection message. On the other hand, the exchange 12 also determines that the disconnection message transmitted from the main control unit 18e is actually transmitted from the home terminal (home terminal 15b), and transmits a release request message to the disconnection message. .

The transmission control unit 18d, having received the release request message from the home terminal 15a, supplies this release request message to the main control unit 18e instead of transmitting it to the exchange 12 via the first communication interface 18a. . The reception control unit 18c that has received the release message from the exchange 12 also supplies this release message to the main control unit 18e instead of transmitting it to the home terminal 15a via the second communication interface 18b. When receiving the release message from the home terminal 15a via the transmission control unit 18d, the main control unit 18e transmits a release completion message to the home terminal 15a via the second communication interface 18b to the reception control unit 18c. Issue a command. Further, when the release message from the exchange 12 is received through the reception control unit 18c, the transmission control unit 18d receives the release message from the exchange 1 via the first communication interface 18a.
2 sends a command to transmit a release completion message.

When viewed from the home terminal 15a, this is equivalent to a release completion message being returned from the exchange 12 in response to the release request message issued by the terminal 15a. This is equivalent to returning a release completion message from the home terminal 15a to the release request message.
2 is released, and one B channel for the security terminal 20 is secured. The home terminal 15b that is communicating using another channel can continue the communication without being affected by these processes.

As described above, the forced line connection device 18 functions as the exchange 12 when viewed from the home terminal.
From the viewpoint of 2, it functions as a home terminal, so that one of the B channels in use is released in the same procedure as the normal disconnection sequence, so that communication between the security terminal 20 and the monitoring center 10 can be established. Become.

FIG. 4 shows another configuration of the forced line connection device 18 in this embodiment. The difference from the configuration shown in FIG. 1 is that the second communication interface 18b
Is provided with a relay P, and by disconnecting the relay P, the connection between the home terminals 15a and 15b and the exchange 12 can be physically disconnected (layer 1 level disconnection). The technique of physically disconnecting in this manner is the same as that of the related art. However, in this embodiment, the security terminal 20 is connected to the exchange 12 and the home DSU 1.
The security terminal 20 is connected to the compulsory line connection device 18 provided between the communication terminals 4 and disconnects the line by operating the relay P of the second communication interface 18b. Reception control unit 18
c, transmission control unit 18d, first communication interface 1
The difference is that it is connected to the exchange 12 and further to the monitoring center 10 via 8a.

Data is exchanged between the security terminal 20 and the monitoring center 10 using a D-channel packet. Based on the D-channel data, the monitoring center 10 operates normally when the security terminal 20 operates normally. Make sure you have Therefore, as in the prior art shown in FIG.
If the security terminal is connected to the point and the relay 16a is provided between the home DSU 14 and the security terminal and is forcibly disconnected, the D channel of the security terminal 20 is also disconnected at the same time.
The monitoring center 10 cannot confirm whether or not the security terminal is operating normally.

However, as shown in FIG. 4, by providing the relay P in the second communication interface 18b, the D channel of the security terminal 20 can maintain the connected state even if the line is physically disconnected. The monitoring center 10 can continuously confirm the state of the security terminal 20 by the packet communication of the D channel.

When the line is physically disconnected as in the configuration of FIG. 4, all the channels are disconnected as in the conventional case, and all the in-home terminals 15a and 15b cannot communicate. When the channel for the security terminal 20 cannot be secured by the method shown in FIG. 2 or FIG. 3 for some reason, or when two channels are required to make an emergency call depending on the type of emergency detected by the security terminal 20 It is desirable to operate the relay P during the operation. After the relay P is operated and physically disconnected, the main control unit 18e makes a call again and establishes communication with the monitoring center 10.

After the communication between the security terminal 20 and the monitoring center 10 is established, the relay P is connected, and the communication of the home terminal 15a or the home terminal 15b is restored using a channel not used by the security terminal 20. be able to.

FIG. 5 shows a line disconnection process and a line connection process in the configuration of FIG. Packet communication using the D channel is always performed between the security terminal 20 and the monitoring center 10. The in-home terminal 15a communicates with the communication destination A via the exchange 12 using the B1 channel. Communication is performed with the communication destination B using the B2 channel.

When two B channels are in use,
When the security terminal 20 detects an emergency, it sends the information to the forced line connection device 18. Forced line connection device 18
Transmits a call setup message to the exchange 12, but the exchange 12 returns a message indicating that there is no free channel because all channels are in use. The main control unit 18e of the forced line connection device 18 that has received the message indicating that there is no free channel from the exchange 12 operates the relay P to forcibly disconnect the line, and releases the B1 channel and the B2 channel. At this time, the security terminal 20 and the monitoring center 10
The D channel between them remains connected via the forced line connection device 18 and does not affect packet communication using the D channel.

After disconnecting the B1 and B2 channels, the forced line connection unit 18 makes a re-call to the exchange 12 based on the information transmitted from the security terminal 20, and performs call setting, call setting acceptance, calling, and response. Communication with the monitoring center 10 is established.

As described above, even when the ISDN line is physically disconnected to secure the channel for the security terminal 20, the D channel between the security terminal 20 and the monitoring center 10 can be established by disconnecting the security terminal 20 downstream. Packet communication can always be ensured, and emergency situations can be transmitted reliably.

[0042]

As described above, according to the present invention, I
Even if an emergency situation is detected by an emergency terminal while all B channels of the SDN subscriber line are in use, communication with the monitoring center can be quickly established and the effect on other terminals in the user's home minimized. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is a layer 2 level explanatory diagram for releasing a used B channel in the configuration of FIG. 1;

FIG. 3 is a layer 3 level explanatory diagram of another method for releasing a used B channel in the configuration of FIG. 1;

FIG. 4 is another configuration block diagram of the embodiment of the present invention.

FIG. 5 is an explanatory diagram of disconnecting a B channel in use in the configuration of FIG. 4;

FIG. 6 is a configuration diagram of a conventional device.

[Explanation of symbols]

10 monitoring center, 12 ISDN exchange, 14 home DSU, 18 forced line connection device, 20 security terminal.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Teramoto 6-11-23 Shimorenjaku, Mitaka City, Tokyo Inside Secom Corporation (72) Inventor Masato Makiyama 6-11-23 Shimorenjaku, Mitaka City, Tokyo Secom Inside (72) Inventor Yasuhisa Ikeda 20-1 Sakuraoka-cho, Shibuya-ku, Tokyo Infosta War Building 18F Inside NTT Electronics Corporation (72) Yoshio Korenaga 20-1 Sakuragaoka-cho, Shibuya-ku, Tokyo Infosta Warville 18F NTT Electronics Corporation (72) Inventor Shigeo Matsuo 8-14-24 Nishi-Shinjuku, Shinjuku-ku, Tokyo NTT-Fanette Systems Incorporated (72) Inventor Kenji Maezawa 8-14-24 Nishi Shinjuku, Shinjuku-ku, Tokyo NTT FANNET SYSTEM F term (reference) in the company 5C087 AA02 BB58 DD02 DD03 DD08 DD20 DD33 EE07 EE14 FF30 GG07 GG55 GG67 GG70 5K030 HC05 JA08 JL08 LC16 LE05 5K101 KK14 LL03 MM04 QQ13 RR14 RR25 RR27 CCTTCC 9A001 CC

Claims (6)

[Claims] 1. A home terminal connected to a home DSU and an IS
A forced line connection device for releasing communication with a DN exchange and establishing communication with an emergency terminal, comprising: line connection means connected between the ISDN exchange and the home DSU; The in-house DS
U is connected to the line connection means without using U. When the home terminal uses all the B channels of the subscriber line of the ISDN line, any of the B channels in use is used. A forced line connection device, wherein the device is released to establish communication with the emergency terminal. 2. The system according to claim 1, wherein the line connection unit releases any one of the B channels by blocking an RR monitoring frame transmitted and received between the home terminal and the ISDN exchange. Line connection equipment. 3. The forced line connection apparatus according to claim 1, wherein said line connection means releases any one of the B channels by transmitting a disconnection message to said home terminal and said ISDN exchange. . 4. The line connection means includes: a first communication interface unit connected to the ISDN exchange; a second communication interface unit connected to the home DSU; and a terminal interface to which the emergency terminal is connected. A reception control unit connected between the first communication interface unit and the second communication interface unit for controlling a signal from the ISDN exchange; and a second communication unit with the first communication interface unit A transmission control unit connected to an interface unit for controlling a signal to the ISDN exchange; and a main control unit for releasing any of the B channels in use by controlling the reception control unit and the transmission control unit. The forced line connection device according to any one of claims 1, 2, and 3, further comprising: 5. A home terminal connected to a home DSU and an IS
A forced line connection device for releasing communication with a DN switch and connecting an emergency terminal, comprising: line connection means connected between the ISDN switch and the home DSU, wherein the emergency terminal is the home DSU Is connected to the ISDN line via the line connecting means without passing through the in-home DSU between the point where the emergency terminal is connected to the ISDN line and the in-home DSU.
A forced line connection device comprising relay means for disconnecting the U from the ISDN exchange. 6. The line connection unit, a first communication interface unit connected to the ISDN exchange, a second communication interface unit connected to the home DSU and including the relay unit, and the emergency terminal A terminal interface unit connected to the first communication interface unit, a reception control unit connected between the first communication interface unit and the second communication interface unit for controlling a signal from the ISDN exchange, and the first communication interface A transmission control unit connected between the communication unit and a second communication interface unit for controlling a signal to the ISDN exchange; controlling the reception control unit and the transmission control unit; DSU and the ISD
The forced line connection device according to claim 5, further comprising: a main control unit that disconnects the connection with the N exchange.