JPH0667018B2 - Exchange system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digital switching system for processing a digital subscriber line signal which is transmitted / received through an out channel and has a layer structure, and in particular, ISDN specified in CCITT Recommendation I series. It relates to a digital switching system for processing digital subscriber line signals.

[Prior Art] ISDN digital subscriber line signals have a hierarchical structure, and are divided into layer 1 (physical layer), layer 2 (data link layer), layer 3 (network layer) and above.

Layer 1 is processed by a transmission device such as a network terminating device or a switching terminating device, and layers 2 and above are processed by a switching device.
At this time, the system for processing the ISDN digital subscriber line signal in the switching apparatus is a system in which the processing of all layers is performed in the subscriber concentrating stage, and for example, in the subscriber concentrating stage, layer 1 is used.
The processing of layers 2 and above is divided into two types, that is, a method of time-division multiplexing digital subscriber line signals to output to the distribution stage and processing in a concentrated manner at the distribution stage.

FIG. 2 is a block diagram of a switching system of the above type.

The subscriber terminal 10 _1, 10 _2, ..., 10 _n and the network terminating device 20 _1, 20 _2, ..., 2
0 _n is installed in the subscriber's house and the subscriber terminals 10 ₁ , 10 ₂ , ..., 10
_n is network terminating device _{20 1, 20 2, ...,} 20 n and the subscriber line _{1 1, 1 2, ...,} 1 n
Are housed in the exchange termination devices 30 ₁ , 30 ₂ , ..., 30 _n , respectively. The subscriber concentrator stage 40A comprises a concentrator switch 41, a digital subscriber line signal processing device 42 and a controller 43, and performs call concentrating and distributing. The distribution stage 50A includes a distribution switch 51 connected to the concentrator switch 41 by the trunk line group 2a, connected to another station by the trunk line group 3, and a control device 52 connected to the control device 43 by the trunk line group 2b. Relay line group
Connect the line between 2a and the trunk line group 3.

FIG. 3 is a block diagram of a switching system of the above type. In this switching system, the subscriber concentrator stage 40B comprises a concentrator switch 41 and a multiplexer / demultiplexer circuit 44, and the distributor stage 50B comprises a distributor switch 51, a digital subscriber line signal processor 52 and a controller 54.

Although a plurality of concentrating stages are actually accommodated in one distributing stage, only one concentrating stage is shown in the systems of FIGS. 2 and 3.

[Problems to be Solved by the Invention] Among the conventional switching systems described above, the system shown in FIG. 2 processes all layers of the ISDN digital subscriber line signal in the subscriber line stage, so It is necessary to install the digital subscriber line signal processing device 42 and the control device 43 in the stage 40A, and when the number of subscribers accommodated in each concentration stage is small, the amount of hardware increases relatively, and the system as a whole is economical. There is a drawback that the structure cannot be assembled.

Further, in the conventional switching system shown in FIG. 3, only the ISDN digital subscriber line signal needs to be time-division multiplexed at the subscriber line concentrating stage 40B and the subscriber line concentrating signal is processed at the distributing stage 50B. The problems of the system shown in the figure disappear. However, since subscriber line signals generally have low traffic, the required number of lines in the trunk line group 2b, which is determined by the number of signals that must be transferred between the subscriber concentrating stage 40B and the distributing stage 50B, is far greater than the number of accommodated subscribers. Although the number of lines required in the conventional switching system shown in FIG. 3 is the same as the number of accommodated subscribers, the cost of the relay line increases and the system as a whole is not economical. .

[Means for Solving the Problems] The switching system of the present invention is a concentrating switch for concentrating the communication information sent from the subscriber side and connecting it to the trunk line group connected to the distribution switch at the distribution stage. And an address field adding means for adding information for the subscriber to the address field of the ISDN digital subscriber line signal which is the control information sent from the subscriber, and an address field for identifying the subscriber. A queuing means for queuing the ISDN digital subscriber line signal and the ISDN digital subscriber line signal having an address field for identifying the waiting subscriber are connected to the digital subscriber line signal processing device at the distribution stage. Multiplexer circuit that sequentially outputs to the relay line that is present, and the subscriber identity sent from the digital subscriber line signal processing device at the distribution stage. An ISDN digital subscriber line signal to which another address field is added is separated to a subscriber line corresponding to the value of the address field and sent out, and an ISDN digital subscriber output from the separation circuit. A relay which has an address field deletion circuit for deleting the subscriber identification address field from the line signal and outputs the address field to the subscriber line, and which is connected to the line concentrating switch of the subscriber collecting stage. A distribution switch for connecting communication information sent from a line group to a relay line group with another station, and an ISDN added with an address field for identifying a subscriber output from a multiplexing circuit at a subscriber concentration stage. An ISDN digital signal receiver for receiving a digital subscriber line signal and having an address field for identifying a subscriber added to a separation circuit of a subscriber concentration stage. A digital subscriber line signal processing device which outputs a subscriber line signal and centrally processes layers 2 and above of an ISDN digital subscriber line signal, and a control device which controls the distribution switch and the digital subscriber line signal processing device. The distribution stage has.

In this way, an address field for identifying a subscriber is added to the ISDN digital subscriber line signal to transmit / receive the signal between the subscriber concentrating stage and the distributing stage, and a waiting means is provided in all stages of the multiplexing circuit. Therefore, it is possible to reduce the number of relay lines between the subscriber concentrating stage and the distributing stage to the same level as the method in which all layers are processed in the subscriber concentrating stage, and the digital subscriber line provided in the distributing stage. Since the number of lines connected to the signal processing device is much smaller than the number of accommodated subscribers, the digital subscriber line signal processing device has a small amount of hardware and can realize an economical digital switching system.

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

In the switching system of this embodiment, the subscriber concentrating stage 40 comprises a concentrating switch 41, an address field adding circuit 47, a multiplexing circuit 49, a waiting queue 48, a separating circuit 45 and an address field deleting circuit 46, and a distributing stage 50. Consists of a distribution switch 51, a control device 54 and a digital subscriber line signal processing device 55.

The switching terminal devices 30 ₁ , 30 ₂ , ..., 30 _n are subscriber terminals 10 ₁ , 1
The information sent from 0 ₂ , ..., 10 _n is separated into communication information and control information ISDN digital subscriber line signals. The communication information from the subscriber terminals 10 ₁ , 10 ₂ , ..., 10 _n is separated by the switching terminating equipment and sent to the concentrator switch, and the ISDN digital subscriber line signal as control information is sent to the address field adding circuit 47. To be

The address field adding circuit 47 includes subscriber terminals 10 ₁ , 10 ₂ ,
..., replace the 10 _n termination device 30 _1, 30 _2, ..., an address field for the subscriber identity before the address field following the start flag of the ISDN digital subscriber line signal transmitted through 30 _n Add the serial number of the exchange termination device. The position to be added may be any position that is uniquely determined, such as immediately after the address field. Further, the information to be added does not have to be the serial number of the exchange terminating device as long as it has a value that can uniquely specify the subscriber accommodated in the subscriber concentrator. The multiplexing circuit 49 multiplexes the digital subscriber line signal added with the address field and outputs the multiplexed signal to the distribution stage 50. The waiting queue 48 waits until the trunk line group 2b becomes empty when the digital subscriber line signal added with the address field is multiplexed by the multiplexing circuit 49. The digital subscriber line signal processing device 55 is controlled by the control device 54, receives the ISDN digital subscriber line signal added with the address field for identifying the subscriber from the multiplexing circuit 49, and separates the subscriber concentrating stage 40. ISD with address field for subscriber identification added to circuit 49
The N digital subscriber line signal is transmitted, and layers 2 and higher of the ISDN digital subscriber line signal are centrally processed in the distribution stage 50. The separation circuit 45 separates the digital subscriber line signal sent from the distribution stage 50 and added with the address field for identifying the subscriber into the subscribers corresponding to the value of the address field. The address field deletion circuit 46 deletes the address field of the subscriber line signal output from the separation circuit 45, and exchanges terminations to the subscriber lines 1 ₁ , 1 ₂ , ..., 1 _n corresponding to the value of the address field. The subscriber line signal is output via the devices 30 ₁ , 30 ₂ , ..., 30 _n .

[Effects of the Invention] As described above, according to the present invention, an ISDN digital subscriber is added by a digital subscriber line signal processing device provided in a distribution stage by adding or deleting an address field to a digital subscriber line signal at a subscriber concentrating stage. By centrally processing layers 2 and above of the main line signal, the number of digital subscriber line signal processing devices can be reduced, and since the waiting means is provided in the preceding stage of the multiplexing circuit, the subscriber concentrating stage and the distribution line can be distributed. The number of relay lines to and from the corrugation is small, and there is an effect that an economical digital switching system can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the exchange system of the present invention, and FIGS. 2 and 3 are block diagrams showing a conventional example. 1 ₁ , 1 ₂ , ..., 1 _n : Subscriber line, 2a, 2b: Relay line group, 3: Relay line group with other station, 10 ₁ , 10 ₂ , ..., 10 _n : Subscriber terminal, 2
0 ₁ , 20 ₂ , ..., 20 _n : Network terminator, 30 ₁ , 30 ₂ , ..., 30 _n : Switching terminator, 40: Subscriber concentrator stage, 41: Concentrator switch, 4
5: Separation circuit, 46: Address field deletion circuit, 47:
Address field addition circuit, 48: Waiting queue, 49:
Multiplexing circuit, 50: distribution stage, 51: distribution switch, 54: control device, 55: digital subscriber line signal processing device.

Claims (1)

[Claims] 1. A subscriber concentrating stage for concentrating and distributing calls of ISDN subscribers, between trunk line groups from the subscriber concentrating stage, and between the trunk line group from the subscriber concentrating stage and other stations. A switching system having a distribution stage for connecting a line to a relay line group, collecting communication information sent from a subscriber side, and connecting to a relay line group connected to a distribution switch at the distribution stage. A concentrator switch, an address field adding means for adding information for the subscriber to the address field of the ISDN digital subscriber line signal which is the control information sent from the subscriber, and an address field for identifying the subscriber Was I
The queuing means for queuing the SDN digital subscriber line signal and the ISDN digital subscriber line signal to which an address field for waiting the subscriber is added are connected to the digital subscriber line signal processing device at the distribution stage. The ISDN digital subscriber line signal added with an address field for identifying the subscriber sent from the digital subscriber line signal processing device at the distribution stage, and the multiplexer circuit for sequentially outputting the signal to the relay line. A separating circuit for separating and transmitting to the subscriber line corresponding to the value of the field, and an address field for identifying the subscriber is deleted from the ISDN digital subscriber line signal output from the separating circuit, and the subscriber line concerned. The subscriber concentrator has an address field deletion circuit for outputting to the subscriber concentrator and is connected to the concentrator switch of the subscriber concentrator. A distribution switch that connects the communication information sent from the trunk line group to another station to the trunk line group with another station, and an address field for identifying the subscriber output from the multiplexing circuit at the subscriber concentration stage are added. The received ISDN digital subscriber line signal is received, and an address field for identifying the subscriber is added to the separation circuit of the subscriber concentrator stage.
A digital subscriber line signal processing device that outputs an SDN digital subscriber line signal and centrally processes layers 2 and above of an ISDN digital subscriber line signal, and a control device that controls a distribution switch and a digital subscriber line signal processing device An exchange system in which the distribution stage has and.