JPH06276250A - Control channel multiplex system - Google Patents

Abstract

PURPOSE:To provide a control channel multiplex system in which reliability can be improved by using a stand-by control channel without necessitating a switching procedure when a normal control channel is present at the time of the occurrence of the fault of any control channel, and a quality can be improved by preventing the disconnection of the control channel at the time of switching, in a communication system in which the control channels are shared by plural interfaces. CONSTITUTION:In the communication system in which plural interfaces 3 and 4 are respectively connected to interfaces 13 and 14, and the control channels on the plural interfaces are shared, control channels 9 and 10 are provided on at least two interfaces, and a control signal is broadcast-communicated from a signal processor 2 at a calling side to the plural control channels 9 and 10 by using the same calling number. Then, a signal processor 12 at an incoming side is equipped with a function which selects the control signal of the plural control channels 9 and 10, and the overlapped signal is removed by the classification and calling number of the signal reaching the plural control channels 9 and 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control channel multiplexing system in a communication system in which a plurality of interfaces share a control channel.

[0002]

2. Description of the Related Art In a communication system in which a plurality of interfaces are connected to the same subscriber, D
Since the channel controls only the calls corresponding to the channels on the interface including the D channel, if one signal path fails, only the call on that interface needs to be out of control. Since this is a control of, the division loss occurs.

On the other hand, in the non-compliant signal system, since the channels on a plurality of interfaces are controlled by the common D channel, the traffic capacity increases due to the sharing (large group) effect, but the reliability is insufficient. There is a possibility,
The following backup procedure is specified.

That is, in FIG. 4, the failure of the D channel 1 is determined by receiving the DL-release-indication (primitive) from the layer 2. At this time, as an option, an attempt to reset the D channel is made. Is possible,
Otherwise, the D channel is assumed to be faulty.

Two states are defined for any D channel in the backup state, and layer 2 establishes the establishment of the multiframe state by layer 3
When in the TEI assigned state after being periodically requested by, the D channel is called out of service.

When Layer 2 is put in TEI assigned state by Layer 3, the D channel is called maintenance busy state, and during this maintenance busy state, the response to link establishment is DM (disconnect mode). Done by transmission.

If D-channel 1 is faulty and D-channel 2 is not out of service, layer 3 puts D-channel 1 into maintenance busy, starts a timer (T321) and then D-channel 2 SAPI = 0, a DL-set-request (primitive) is sent to reinitialize link 0.

Upon receipt of this primitive, layer 2 sends out a SABME command. Timer (T20
0) is started.

Following the end of receiving the SABME command for D channel 2, the rest of the predetermined (JT-Q931) procedure for establishing the logical link DLCI = 0 is performed.

Here, the logical link DLC of D channel 2
When I = 0 enters the link setup state, the procedure for establishing Layer 3 call control signaling can be initiated on the link.

Then, in order to establish a backup D channel for transferring call control signals, layer 3
Send an appropriate layer 3 message (eg, a "STAT ENQ" message with the call reference).

When the response to the layer 3 message is received, the D channel 2 becomes the activated D channel, normal layer 3 call control signal processing is performed, the timer (T321) is stopped, and D Channel 1 is in the service stopped state.

If the maintenance busy timer (T321) expires before the response to the layer 3 message, D channel 1 goes out of service and a logical link is established for both D channel 1 and D channel 2. DLC
Attempts to establish I = 0. Where D channels 1 and 2
If both logical links DLCI = 0 are simultaneously established, the D channel designated as the first priority is selected as the D channel for transferring the call control signal, and the D channel designated as the first priority is selected. Channels are agreed upon at both sides of the interface at the time of subscription.

After the switching is completed, the existing D channel 2 becomes the new D channel 1, and the existing D channel 1 becomes the D channel 2.

After that, the completion of the appropriate maintenance operation for D channel 2 activates the logical link for SAPI = 0 and 63 at layer 2, and the D channel is moved out of service.

It should be noted that the D channel may be switched again only due to a failure of D channel 1, routing or a maintenance request from a peer entity.

Conventionally, in order to improve the reliability of a control channel of a communication system connected using a plurality of collectively managed interfaces as described above, an unused control channel is prepared on an interface having no control channel. Then, when the control channel fails, the link reconfiguration is attempted, and then the control signal is transferred to the control channel on another interface and used by a switching procedure for activating the control channel on another interface.

[0018]

However, according to the above switching procedure, a temporary control channel interruption is unavoidable, and the backup control channel is not in the operating state at normal times. There is a problem that gender cannot be confirmed.

Therefore, the present invention has been made in view of the above points, and in a communication system in which a control channel is shared by a plurality of interfaces, if there is a normal control channel when any control channel fails, a switching procedure is performed. It is an object of the present invention to provide an improved control channel multiplexing system that can improve reliability because a spare control channel can be used without requiring control and improve quality because control channel disconnection does not occur at the time of switching. .

[0020]

According to the present invention, in a communication system in which a plurality of interfaces are connected to each other and a control channel on the plurality of interfaces is shared,
A control channel is provided on each of at least two interfaces, and a control signal from a signal processing device on the originating side is broadcast to a plurality of control channels by using the same call number, and a control signal on a plurality of control channels is transmitted to the signal processing device on the destination side. There is provided a control channel multiplexing system characterized by discarding duplicate signals depending on the types of signals arriving on a plurality of control channels and call numbers by providing a function for selecting.

[0021]

According to the above means, if a normal control channel exists in the event of any control channel failure, a spare control channel can be used without the need for a switching procedure, so that reliability is improved and control is performed at the time of switching. The quality is improved because no channel disconnection occurs.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of a control channel multiplexing system according to the present invention.

This system functions so that when the same information arrives from a different line within a fixed time, the comparator circuit detects that the information was previously received and discards it. State the content.

That is, in FIG. 1, the communication devices 1, 1
Reference numeral 1 is an interconnection of communication interfaces 9 and 10 including control channels with interfaces 3, 4 and 13 and 14 of signal processing devices 2 and 12 provided therein.

Interfaces 3, 4 and 1 respectively
Reference numerals 3 and 14 are connected to respective call processing units 7 and 17, management units 6 and 16 and service units 8 and 18 through comparison circuits 5 and 15.

According to the present invention, a plurality of control channels are provided on at least two interfaces in a communication system in which a plurality of interfaces are connected to each other as described above and control channels on the plurality of interfaces are shared. Is used simultaneously, a spare control channel can be used without requiring a switching procedure if a normal control channel exists in the event of any control channel failure.

FIG. 2 functionally shows the inside of one of the communication devices 1 or 11 of FIG. 1, and operates as follows.

First, on the other communication device 11 or 1 side, the LAPD 23a, 24b corresponding to any one of the interfaces 3, 4 and 13, 14 and the lower layer management units 23b, 24b are provided with a layer according to a predetermined procedure. Management and distribution of layer information is performed. That is, in the layer 2, the layer 3 information is distributed to a plurality of interfaces with the same contents according to the LAPD procedure including the interface-based sequence management.

This is because when the layer 3 is individually provided, the call number is given to each interface, and therefore it is not possible to identify the same information.

Then, the receiving side sends only one of the same information arriving from a plurality of interfaces to the call processing section 7 or 17 according to the call number on the layer 3 signal.

At this time, the signal processing device 2 or 12 is
In the normal procedure, no interface identifier is given to the interface including the D channel, but in order to distribute the same contents, the interface identifier is given to all interfaces.

Therefore, when the same information arrives from a different line within a certain period of time depending on the presence or absence of the interface identifier, the comparison circuit 5 or 15 detects that it is the previously received information and discards it. can do.

That is, according to the present invention, the switching and switching-back procedure is not required, instantaneous interruption can be avoided, and the channel sharing effect by the plurality of interfaces is not impaired.
Channel reliability is improved.

According to the present invention, there is also an advantage that the interface identifier and the priority D channel are not changed due to the switching back.

FIG. 3 shows an example of the above interface identifier. In this case, the interface identifier includes the contents defined in octets 3 and 3.1 of the channel identifier information element.

That is, in FIG. 3, when the “with / without display of interface identifier” field of octet 3 indicates “interface implicitly identified”, octet 3.1 is omitted.

If octet 3.1 is present, this octet may be extended by using the extension bit (bit 8).

The channel identifier information element is used to identify the channel in the interface.

[0040]

As described above, according to the present invention, in the communication system in which the control channels are shared by a plurality of interfaces, a switching procedure is required if a normal control channel exists in the event of any control channel failure. Therefore, it is possible to provide an improved control channel multiplexing method so that the spare control channel can be used without failing to improve the reliability and the quality is improved because the control channel is not disconnected at the time of switching.

[Brief description of drawings]

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

FIG. 2 is a block diagram functionally showing a part of FIG.

FIG. 3 is a diagram illustrating an interface identifier used in the present invention.

FIG. 4 is a diagram for explaining a backup procedure by a conventional non-compliant signal system.

[Explanation of symbols]

 1, 11 ... Communication device, 2, 12 ... Signal processing device, 3, 13, 4, 14 ... Interface, 5, 15 ... Comparison circuit, 6, 16 ... Management unit, 7, 17 ... Call processing unit, 8, 18 ... service section, 9, 10 ... communication line including control channel.

Claims (1)

[Claims] 1. In a communication system in which a plurality of interfaces are connected to a pair of grounds and control channels on the plurality of interfaces are shared, control channels are respectively provided on at least two interfaces, and control is performed from a signal processing device on the originating side. Depending on the type and call number of the signal arriving at the multiple control channels by broadcasting the signal to the multiple control channels using the same call number and providing the receiving side signal processing device with the function of selecting the control signals of the multiple control channels, A control channel multiplexing method characterized by discarding overlapping signals.