JPS58116837A - Multiloop communication system - Google Patents

Abstract

PURPOSE:To improve serviceability by sending an answer from a loop coupler in response to a request to call, etc., from a terminal station device. CONSTITUTION:When the request to call is detected by a terminal station device TN11 in calling from a terminal station connected to the terminal station device TN11 to a terminal connected to a terminal station device TN21, a signaling frame showing the request to call is sent out. When the frame is received by the loop coupler UX, the UX sends it to a lop where the TN21 is connected according to a loop address. On the reception, the TN21 checks whether a terminating terminal is held readiness for communication or not and sends out an answer signaling frame. This signaling frame when sent out of the TN21 is received by TN11 according to a procedure reverse to said procedure. This system shortens answer waiting time extremely when an opposite loop is not ready for communication between loops, and also judges the cause of disabled communication easily.

Description

Detailed Description of the Invention (b) Technical Field of the Invention The present invention relates to a multi-loop communication system that performs inter-loop communication in a digital communication network consisting of a large number of loop-shaped transmission paths of a number of values. This paper relates to a multi-loop communication system that enables excellent inter-loop communication.

(b) Background of the technology In recent years, in the field of communications, there has been a demand for improving the serviceability of communication networks. They are required to improve their sexual abilities.

(c) Conventional technology and problems A conventional multi-loop communication system will be explained using FIG.

FIG. 1 is a diagram showing an example of the configuration of a multi-loop communication network. In the figure, SV to Sv4 are loop monitoring devices, TN,...
t TN,, t TN*+t TN,, l TN, II
TNa*tTNas? TN, , is a terminal device, and LX is a loop coupling device.0 Now, when transmitting and receiving communication data between nine terminals (not shown) connected to the terminal device TNIl and terminal device TNt, respectively, first , the terminal station device TN, which is the terminal device on the transmitting side, loop-coupling the signaling frame indicating the address, etc. indicating the other terminal station device) L
(0), the loop coupling device LX relays the frame signaling frame to the loop connected to the other end station device TN, and the above communication data is transmitted to the end station device TN.
However, the conventional multi-loop communication system has the following drawbacks. In other words, when a terminal device in another loop sends a signaling claim to a loop that cannot transmit or receive 7 frames due to a transmission path failure, etc., the means to know that the terminal device is unable to communicate is to wait for a response. Since there is only a time act based on a monitoring timer, this leads to a decrease in serviceability, such as an increase in waiting time until it is known that the connection is not possible, and the reason for the failure being unknown. When providing a representative number service in which connection requests are sequentially issued to terminal equipment, there is a particular drawback that an increase in waiting time O becomes a major problem.

(d) Objective of the Invention An object of the invention is to provide a multi-loop communication system with excellent serviceability by transmitting a response from a loop coupling device to a call request, etc. from a station device. ) In a multi-loop communication system that uses signaling 7 frames for connection and disconnection of lines in a digital communication network configured by interconnecting loops having a terminal station device and a loop monitoring device by a loop coupling device, the loop coupling A state in which the destination loop of the Mukuro signaling 7 frame cannot be over-relied by the above means when the device receives a connection request for the line that requires 2 loops Kt from the calling terminal device. The device is characterized by being provided with a means for generating and transmitting a signaling claim to the scissors calling terminal device to the effect that connection to the destination loop is impossible when it is detected that the device has died. .

(f) Embodiment 1s of the Invention The multi-loose communication system of the present invention will be explained in detail with reference to FIGS. 1 to 4.

FIG. 2 is a diagram showing an example of a signaling frame format. In the figure, CTL is a control code indicating whether all 7 frames are signaling claims, 7 data frames, or an empty frame, DA section is an address indicating the destination of the complaint (hereinafter referred to as address DA), and OA
part is an address indicating the sending source of the frame (hereinafter referred to as address OA), LPA is a loop address, NDA is a terminal device address, CHA is a terminal address, CMM is a control code indicating a request/response between terminal devices, DT is the control code CMM
This is data representing additional information related to.

FIG. 3 is a diagram showing the configuration of the loop coupling device LX. In the figure, 1 is a switching circuit, a two-wire control circuit, 3 to 6 are loop coupling circuits, and 7 is a switching path.

FIG. 4 is a flowchart showing the operation of the control circuit.

Here, as an example of inter-loop overconfidence in the multi-loop communication network shown in Figure 1, we will take the case where a call is made from a terminal connected to terminal equipment TN, , to a terminal connected to terminal equipment fTN□. He explains.

First, in the terminal device TN, , the terminal device TN,.

When a call request is detected from a terminal connected to a terminal, the terminal equipment TN, checks the state of the connected loop, etc., and if communication is possible, sends a signaling frame representing a call request, that is, as shown in Fig. 2. Generate a signaling frame and send it to the loop.

Here, the signaling claim sent at that time is sent with the content shown below. That is, the control code CTL shown in FIG. 2 is set with a code indicating that the signaling frame is in use, and the address DAK is set with the loop address to which the terminal equipment TN is connected to the loop address LPA. Station device address NDAK
The node address of TNn and the terminal address of the communication destination are set in the terminal address CHA. Regarding address OA, loop address LPAK terminal equipment N
Set the local loop address to which 11 is connected, the local node (terminal device TN,...) address in the terminal device address NDA, the calling source terminal address in the terminal address CHA, and the control code CMM. , set the call request code ◇ In this case, the content #i of address DT is not particularly set.

When the above-mentioned signaling frame is transmitted from the terminal device TN, the destination loop is another loop, so the loop coupling device LX receives the received signaling claim. According to the loop address LPA of the address DA, it is transmitted to the loop to which the terminal device TN□ is connected. Subsequently, the signaling frame 7 is received by the terminal device TN□, and the terminal device TN, , refers to the control code CMM of the signaling frame,
It is connected to terminal equipment TN□ and learns that a call request has been made to nine terminals.

The terminal device TN, checks whether the called terminal can communicate or not, and sends out seven response signaling frames as shown below. The address DAK is set to the address OA of the received signaling frame, the address OA is set to the address DA of the received signaling claim, and the control code CMM is set to the expanded connection possible response code when the terminal can communicate, and when the terminal cannot communicate. sets the connection not possible response code.

Furthermore, in the case of a connection failure response, the reason for connection failure is set in the DT.

When the frame is sent from the terminal station TN, it is received by the terminal device TN by following the procedure reverse to that for the call request signaling frame. Then, the terminal device TN, , checks the control code CMMt-# of the signaling frame to determine whether or not communication is possible. In normal cases, the above procedure is used to receive a signaling frame that spans between loops. A handover will take place.

Next, the operation of the loop coupling device will be explained in detail.

In FIG. 3, a control circuit 2 manages the state of the loop coupling device LX, performs acknowledge processing for received signaling frames, and the like. Exchange circuit 1 is received! 0-loop coupling circuits 3 to 6, which perform exchange control such as determining the destination loop and generating exchange timing for frames, are provided for each loop, and are synchronized with the basic clock on the loop to control the exchange circuit 1. It receives, exchanges, and sends frames below.

Furthermore, the loop coupling circuits 3 to 6 have a function of detecting occurrence/recovery of a loop failure and notifying the control circuit 2 of the occurrence/recovery.

If there is a frame addressed to another loop in the loop, the loop coupling circuits 3 to 6 receive the frame and issue a frame exchange request to the exchange circuit l.0 In the exchange circuit 1, the received frame is a 7 signaling frame. If it is a data/7 frame, the same 7 frames are sent to the control circuit 2, and if it is a data/7 frame, the exchange path 7 is sent to the loop coupling circuit of the destination loop of the 7 frames.
Transfer via The loop coupling circuit to which the frame is transferred via the exchange path 7 sends the same claim to an empty frame on the loop.

On the other hand, after analyzing the transferred signaling frame, the control circuit 2 normally sends it to the destination loop without manipulating the contents of the received signaling frame.
In addition, when transmitting a signaling frame from the control circuit 2, the same circuit issues a 7 frame exchange request to the switching circuit 1, and the switching circuit 1 transfers the 7 signaling frames to the loop coupling circuit, and then the loop coupling circuit and the loop. Send.

Here, the operation of the loop coupling device LX when communication becomes impossible due to the occurrence of damage to the loop 2 to which the terminal devices TN, . . . are connected in the above example will be described.

The call request signaling frame received by the loop coupling device LX in the above procedure is transferred to the control circuit 2. The control circuit 2 has previously been notified by the loop coupling circuit 2 of the loop to which the terminal equipment TN is connected that a failure has occurred in that loop, and the call request is not accepted. I understand that it cannot be attached. Therefore, control circuit 2
w! is addressed to the caller in the following format: : Generates and transmits a non-continuation response signaling frame. Address DA and address OA set the contents of address OA and address DA of the received signaling frame, respectively. The CMM sets a connection not possible response code. DT
A code indicating the reason why connection is not possible is set in the section.

When the above-mentioned signaling frame is received by the terminal device TN11, the terminal device TNII knows that the tSO* connection is not possible, and can perform terminal control and internal processing. Therefore, communication control can be performed without spending unnecessary waiting time. Furthermore, the loop coupling device 1
Since the source address of the 9II connection failure response signaling frame 7 sent from the LX is the destination of the call, the calling side terminal equipment TNII processes the signaling frame 11.
There is no need to be conscious of the existence of the loop coupling device LX, and the control logic can be the same as the conventional method. Furthermore, the present example of IIA has a means for displaying various messages from the TM, and displays 9 messages according to the reason code included in the connection failure response signaling frame. For example, in the above example, if the terminal device TN21 notifies the terminal that the terminal is in use and is unable to connect, it will display rBU8YJ, and if the response from the loop coupling device LX that the connection is not possible due to a failure, it will display rLN CLO8KJ. This makes it easier for the user to decide on subsequent measures, further improving serviceability.

Further, the fourth @ is a diagram showing a flowchart of a control circuit within the loop coupling device. In the control circuit, as explained above, after the signaling frame is damaged, this signaling frame is disassembled. Then, it is determined whether or not the destination loop indicated in the signaling frame is in operation, and if it is in operation, the signaling frame is sent to the destination loop, and if it is not in operation, i.e. If there is a failure, etc., it generates a non-responsive signaling frame, analyzes the reason for the non-response, and sends the signaling frame to the source loop.

Billion) More than the effects of the invention, detailed Kl! As explained above, according to the multi-loop communication method of the present invention, when the other loop of inter-loop communication cannot communicate, the response waiting time can be extremely shortened, and the cause of communication failure can be easily determined. It is possible to obtain the effect that the serviceability of the correspondence system can be improved.

[Brief explanation of drawings]

IElm is a diagram showing an example of the configuration of a multi-loop communication network, No. 211
shows an example of a signaling frame format −,
FIG. 3 shows the configuration of the loop coupling device, and FIG. 4 is a flowchart showing the operation of the control circuit. In the figure, SV to 8Va are loop monitoring devices, TNtse
TNtt, TNtte TNTs TNmse T
NsaeTN41. TM01 is a terminal device, LX is a loop coupling device, l is a switching circuit, 2 is a control circuit, 3 to 6 are loop coupling circuits, and 7 is a switching path. 81 Diagram 2 Diagram 3 Diagram No. 4

Claims (1)

[Claims] In a multi-loop communication system that uses 7 frames of signaling to connect and disconnect lines in a digital communication network that is constructed by mutually connecting loops (including terminal equipment and loop monitoring equipment) using a loop coupling device, the loop coupling The device has a means for detecting whether communication is possible in each loop, and when it receives a connection request for a line spanning two loops from a calling terminal device,
If the above means detects that the destination loop of the armpit signaling frame has an IC in which communication is not possible, a 7-frame signal is generated to the calling terminal station indicating that connection to the destination loop is not possible. A multi-loop communication method in which the means for transmitting and transmitting data is set up in nine different ways.