JP2508961B2 - ISDN remote system - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a remote device for an ISDN switch.

[0002]

2. Description of the Related Art A conventional ISDN remote device has a Dc for processing an ISDN call control signal (Dch) in the device.
Either the h processing unit is provided or the ISDN exchange is provided with the Dch processing unit, and the Dch signal is transferred from the remote device through a fixed number of channels.

As a data transfer control method in ISDN, a data link service interface and an IS are used.
Between the DN interface, a data transfer amount monitoring means for monitoring the state of the data transfer amount and a variable link multi-link control means for controlling the number of data transfer paths are provided, which are connected via ISDN according to the data transfer amount. There is known a method of controlling the data transfer by mutually notifying the number of channels used for data transfer of the variable multi-link control means of the two systems (JP-A-63-305644).

[0004]

When an ISDN remote device is provided with a Dch processing section, even if the ISDN subscriber has only one subscriber, each ISDN remote device has a Dch processing unit.
It was not economical because it was necessary to install a processing unit and a large number of devices were required compared to the number of ISDN subscribers.

In addition, the Dch is IS
When transferring to a DN switch, if the band of the transmission channel between the host device and the remote device for transmitting and receiving the ISDN call control signal (Dch signal) is set to be narrow,
Delay for transmitting the call
There have been problems such as an increase in packet transmission delay and a shortage of channels for communication when a wide band is set.

It is an object of the present invention to provide an ISDN remote system in which the number of devices for the Dch processing unit is small, the Dch can be transferred with a small delay, and there is no shortage of channels for communication.

[0007]

The ISDN remote system of the present invention is multiplexed with an ISDN subscriber circuit and a Dch multiplexer for multiplexing the Dch signal of each ISDN subscriber circuit to the speed of an arbitrary number of channels. A call path switch for connecting a Dch signal to a transmission path, an ISDN remote device including the ISDN subscriber circuit, the Dch multiplexing unit, and a control unit for controlling the call path switch, and the ISDN remote device that is multiplexed and transmitted. A Dch processing unit that processes the Dch signals that have been placed on the path while being multiplexed, a speech path switch that connects the Dch processing unit and the transmission path, and a Dch
A control channel number counter for holding the number of channels allocated to the transmission of a channel, a free call channel number counter for holding the free channel number of a transmission path that can be used for a call, the Dch processing unit, the call path, and both counters. And a remote connection device including a control unit for controlling, when the control unit of the remote connection device needs to newly allocate a channel of a transmission line to a call, the value of the control channel number counter and the idle call The channel counter is checked, and if the value of the idle call channel counter is 0 and the value of the control channel counter is 1, it informs the call processing device that the call processing cannot be continued because the channel is busy.
If the value of the idle call channel number counter is 1 or more, one channel is selected from the channels not allocated for Dch transfer among the channels of the transmission path and not already allocated for the call. And assign the value of the idle call channel counter to 1
The value of the idle call channel counter is 0,
If the value of the control channel number counter is 2 or more, D
From the channels allocated for ch transfer, control is performed to reallocate one channel for communication, and
The value of the control channel number counter is decremented by one, and when a channel not used for communication occurs, the value of the control channel number counter is checked and the value of the control channel number counter can be processed by the Dch processing unit. If the number of channels up to the maximum speed is reached, the channel allocated for communication is released to make it available for communication, the value of the idle communication channel number counter is incremented by 1, and the control channel number counter is increased. Is the value of Dc
h If the number of channels up to the maximum speed that can be processed by the processing unit is smaller than the number of channels allocated for communication, Dc
It is provided with means for performing re-allocation control for h transfer and incrementing the value of the control channel number counter by one.

[0008]

By installing the Dch processing unit in the remote connection device, only one Dch processing unit is required even if the number of ISDN subscribers increases. In addition, by varying the number of channels to be assigned to Dch transfer depending on the presence or absence of channels used for a call, the maximum number of channels can be assigned to Dch transfer without affecting the call. Therefore, Dch can be transferred with a small delay, and call processing can be realized at high speed.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of an ISDN remote system according to an embodiment of the present invention.

The ISDN remote device 1 includes ISDN subscriber circuits 5 and 6, a Dch multiplexer 7 that multiplexes the Dch signals of each ISDN subscriber to the speed of an arbitrary number of channels, and the multiplexed Dch signals. The speech path switch 8 connected to the transmission path 15 between the remote connection device 2 of the exchange and the ISDN remote device 1, the ISDN subscriber circuit 5,
6, a Dch multiplexing unit 7, and a control unit 9 that controls the communication path switch 8. The remote connection device 2 of the ISDN exchange connects the Dch processing unit 12, which processes the Dch signals multiplexed by the ISDN remote device 1 and placed on the transmission line 15 while the signals are multiplexed, and the Dch processing unit 12 and the transmission line 15. A call path switch 10, a control channel number counter 13 that holds the number of channels allocated for Dch transmission, a free call channel number counter 14 that holds the number of free channels of the transmission path that can be used for a call, and a call path switch 10 , Dch processing unit 12, and control unit 11 for controlling counters 13 and 14. The call connection network 3 is connected to the remote connection device 2, and the call processing device 4 controls the call connection network 3 and the remote connection device 2 to perform call processing.

Next, the channel allocation operation of the ISDN remote system having the above-mentioned configuration will be described.

First, when no call is connected, among the transmission channels between the ISDN remote device 1 and the remote connection device 2, the number of channels up to the maximum speed that the Dch processing unit 12 can process is the control information. (Dch) is assigned for transfer, the transmission line 15 and the Dch processing unit 12 are connected via the communication line switch 8, and the control unit 11 stores the number of channels in the control channel number counter 13,
The remaining channel number is stored in the idle call channel counter 14 as the number of channels used for the call.

Here, as in the case where a call is requested from an ISDN subscriber accommodated in the ISDN remote device 1 or an incoming call occurs to the ISDN subscriber accommodated in the ISDN remote device 1, the transmission line is When it is necessary to newly allocate a channel to a call, the control unit 1
1 checks the value of the control channel number counter 13 and the idle call channel number counter 14, and if the value of the idle call channel counter 14 is 0 and the value of the control channel number counter 13 is 1, it is called as channel busy. It informs the call processing device 4 that the processing cannot be continued, and if the value of the idle call channel number counter 14 is 1 or more, it is not the channel allocated for control information (Dch) transfer among the channels of the transmission path, and One channel is re-allocated as a telephone call from the channels not assigned for the telephone call, and the value of the idle telephone call channel counter 14 is decremented by one. In cases other than the above, that is, when the value of the idle call channel counter 14 is 0 and the value of the control channel counter 13 is 2 or more, the control information (D
ch) The control unit 11 performs the following operation in order to reallocate one channel out of channels allocated for transfer as a call. The control unit 11 controls the Dch processing unit 12 and the speech path switch 10 to reduce the number of control information transfer channels, and then sends an operation start signal to the control unit 9 through the control information channel, and the control unit 9 causes the Dch multiplexing unit. 7 and the communication path switch 8 to reduce the number of control information transfer channels and notify the control unit 11 of the end of the operation. Control unit 11
Decrements the value of the control channel number counter 13 by one.

When it is necessary to reduce the number of channels allocated for a call, such as when a call is disconnected during a call, the control unit 11 checks the value of the control channel number counter 13, and if the control channel is If the value of the number counter 13 is the number of channels up to the maximum speed that the Dch processing unit 12 can process, the channel allocated for the call is released and made available for the call, and the idle call channel number counter 14 Increase the value of by one.
In cases other than the above, that is, the control channel number counter 13
If the value of is smaller than the number of channels up to the maximum speed that can be processed by the Dch processing unit 12, the following operation is performed in order to reallocate the channel allocated for communication as control information (Dch) transfer. The control unit 11 controls the Dch processing unit 12 and the speech path switch 10 to increase the number of control information transfer channels, and then sends an operation start signal to the control unit 9 through the control information channel, and the control unit 9 causes the Dch multiplexing unit. 7 and the communication path switch 8 to increase the allocation and notify the control unit 11 of the end of the operation. The control unit 11 increments the value of the control channel number counter 13 by one.

[0016]

As described above, the present invention is based on ISDN.
In configuring the remote device of DCH processing, the Dch data of the subscriber is transferred to the host station and processed by the Dch processing device installed in the host station, thereby sharing the Dch processing device between the remote device and the ISDN exchange. With this, an ISDN remote device can be realized with a smaller amount of hardware, and the maximum number of channels can be allocated to Dch transfer without affecting the call, and the Dch can be transferred with less delay. Can be transferred and call processing can be realized at high speed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ISDN remote system according to an embodiment of the present invention.

[Explanation of symbols]

 1 ISDN remote device 2 remote connection device 3 speech path network 4 call processing device 5 ISDN subscriber circuit 6 ISDN subscriber circuit 7 Dch multiplexing unit 8 speech path switch 9 control unit 10 speech path switch 11 control unit 12 Dch processing unit 13 Control channel number counter 14 Free call channel number counter 15 Transmission line

Claims (1)

(57) [Claims] 1. A remote ISD in an ISDN exchange.
An ISDN remote system accommodating N subscribers, comprising an ISDN subscriber circuit and Dch of each ISDN subscriber circuit
Controls the Dch multiplexing unit that multiplexes signals at the speed of an arbitrary number of channels, the speech path switch that connects the multiplexed Dch signals to the transmission path, the ISDN subscriber circuit, the Dch multiplexing unit, and the speech path switch ISD including control unit
An N remote device, a Dch processing unit that processes the Dch signals multiplexed by the ISDN remote device and placed on the transmission path while being multiplexed, and a speech path switch that connects the Dch processing unit and the transmission path, A control channel number counter that holds the number of channels allocated for Dch transmission, a free call channel number counter that holds the free channel number of a transmission path that can be used for a call, the Dch processing unit, the call path, and both counters. And a remote connection device including a control unit for controlling the control unit, the control unit of the remote connection device, when it becomes necessary to newly allocate a channel of a transmission path to a call, the value of the control channel number counter and the free space. The call channel number counter is checked, and the value of the idle call channel number counter is 0, and the value of the control channel number counter is If tell inability call processing continues as a channel busy to call processor, the value of the idle speech channel number counter 1
If the above is true, one channel is reassigned as a call from the channels not allocated for Dch transfer in the channels of the transmission path and not already allocated for a call, and the idle call channel number counter is provided. If the value of the idle channel number counter is 0 and the value of the control channel number counter is 2 or more, one channel is assigned from among channels assigned for Dch transfer as a call. When performing control to correct, decrementing the value of the control channel number counter by one, and if a channel not used for communication occurs,
The value of the control channel number counter is checked, and if the value of the control channel number counter is the number of channels up to the maximum speed that can be processed by the Dch processing unit,
The channel allocated for communication is released to make it available for communication, the value of the idle communication channel number counter is incremented by 1, and the value of the control channel number counter reaches the maximum speed that the Dch processing unit can process. If the number of channels is less than the number of channels, the ISDN remote system has means for performing control to reallocate the channels allocated for communication for Dch transfer and increasing the value of the control channel number counter by one.