JPH0432597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switching device in which distributed switches are connected by a ring transmission line.

Conventionally, in order to create a large-scale switching system by connecting multiple distributed exchanges, multiple exchanges EX1, EX2, EX3, EX4, etc. were connected as shown in Figure 1.
They were interconnected by trunk line 1. This required a huge amount of work to install the wiring between the exchanges. As a method to solve this problem, a method has been considered in which a ring-shaped high-speed transmission line (hereinafter referred to as ring transmission line 2) is used in a time division multiplex transmission system as a trunk line between exchanges, as shown in FIG. For the method shown in Figure 2, the third
As shown in the figure, a frame 3 consisting of a plurality of slots SL corresponding to a conventional trunk line circulates on a ring transmission line 2. In this method, for example, EX1-EX2 are exchangers EX1 and EX2, as shown in the figure.
As indicated by the allocation of time slots between exchanges, slot SLs are fixedly allocated between exchanges, so there are cases where it is not possible to relay more than the number of slots allocated to an exchange, or the slots are used inefficiently. There were flaws.

This invention eliminates these drawbacks, and instead of assigning slots to each exchange in a fixed manner, by adding a trunk line management device, slots can be allocated dynamically in response to slot allocation requests from each exchange. The purpose of the present invention is to provide a switching device that improves slot usage efficiency and switching capacity and reduces call losses by allocating slots.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 4 is a configuration diagram showing an embodiment of the switching device of the present invention, in which a plurality of switching devices EX and a trunk line management device SD are connected by a ring transmission path 2. In FIG. FIG. 5 shows the format of the frame 3 on the ring transmission line 2 in one embodiment of the present invention. Frame 3 is a relay slot area RS1, which transmits digital information such as data, audio, and images.
It consists of RSs such as RS2, . . . RSn, and control slot areas CS1, CS2, . These relay slots are used to transmit communication information between terminal devices respectively connected to two exchanges. Therefore, when one switch transmits a relay slot assignment request signal to the trunk line management device, the trunk line management device that receives this sends one trunk slot to the switch and the switch connected to the switch as a partner of the switch. Make assignments.

The trunk line management device receives a relay slot allocation request signal issued from the exchange, checks a table memory that stores the relay slot allocation status, and determines the relay slots that are not allocated to the exchange. The trunk line management device notifies the two exchanges of the number indicating the trunk slot using an assignment signal. The exchange will send and receive information through the relay slot based on the number indicating the relay slot in the received assignment signal. 6th
The figure shows a slot allocation device SD according to an embodiment of this invention.
SR is a transmitting/receiving unit that uses the control slot CS to send and receive control information such as relay slot assignment requests or assignments, PR is a processing unit that performs slot assignment requests or assignment processing, and TM is a relay slot. This is a table memory that stores the allocation status of. Here, the processing unit PR includes a microprocessor and a memory in which a program is stored. Further, this processing PR is connected to a transmitting/receiving unit SR that transmits and receives control information, and exchanges relay slot allocation information with the exchange.
Also, while referring to or rewriting the table memory, vacant relay slots are assigned to exchanges. The table memory TM here is used to manage which relay slot should be used to send the call signal. When a call is terminated, a call termination signal from the exchange is sent to the trunk line management device through the control slot, so this termination signal is relayed to the other party's exchange via the control slot, and the corresponding relay slot is retrieved from the table memory. Change to empty status. Figure 7 is a configuration diagram of the exchange EX.
SA is a slot access section, SC is a slot control section, and SW is an exchange switch section that connects the terminal T and the relay slot. FIG. 8 is a detailed diagram of the table memory TM.

The operation of the switching device of the present invention will be described below with reference to FIGS. 6, 7, and 8.

When the exchange EX has a slot assignment request, a slot assignment request signal is sent from the exchange switch section SW to the slot control section SC via the signal line 701. This slot assignment request signal is sent via the signal line
702, the slot access unit SA, the signal line 2d, and the control slot CS to the trunk line management device SD. Here, we will discuss the allocation of trunk slots, the allocation with the other exchange, and the method of transmitting the allocation request signal with the other exchange.The exchange and the trunk line management device are connected one-to-one through separate slots. ing. For example, CS1 is used only for EX1 and SD, CS2 is used only for EX2 and SD, CS3 is used only for EX3 and SD, CS4 is used only for EX4 and SD, etc. Each slot is fixedly allocated between the exchange and the relay management device. The trunk line management device SD is
The slot allocation request signal is received by the transmitting/receiving unit SR from the signal line 2a and sent to the processing unit PR via the signal line 601.

The processing unit PR refers to the table memory TM and
Allocate unused relay slot RS. This allocation signal is output from the processing unit PR and sent to the exchange EX via the signal line 601, the transceiver unit SR, and the signal line 2b. FIG. 8 is a diagram showing the contents of the table memory TM used for relay slot allocation control. In the figure, relay slot RS1 is connected to exchange EX1-
Between EX2, relay slot RS2 is the exchanger EX
Between 1 and EX2, relay slot RS3 is the exchange
indicates that it is in use between EX3 and EX4, and indicates that relay slot RS4 is vacant.

Returning to FIG. 7, when the allocation signal arrives at the slot control unit SC via the signal line 2c, the slot access unit SA, and the signal line 703, the slot control unit SC
Instructs the slot access unit SA to perform coupling between each assigned relay slot RS and the signal line 704 of the exchange switch SW, and connects the terminal T.
Information can be communicated between them by means of relay slots.

In the above manner, a relay slot is installed between the exchanges.
RS will be assigned.

Slot allocation is done by sending an allocation release request from the exchange EX to the trunk line management device SD, and conversely by sending an allocation release signal from the trunk line management device SD to the exchange EX. Since it is easily understood from the explanation, detailed explanation will be omitted.

In this way, this switching device does not fixedly allocate multiple slots to each switch EX, but instead receives slot assignment request signals from each switch EX.
The slot allocation release request signal is sent to the trunk line management device SD.
The trunk line management device SD sends a slot assignment signal and a slot assignment release signal to the exchange EX, and the necessary number of trunk slots RS is assigned to the exchange EX. Therefore, since all slots can be shared by all exchanges, there is no longer a problem where slots cannot be used by other exchanges due to fixed slot allocation as in the past, and problems caused by insufficient trunk line allocation are eliminated. This greatly reduces the number of missed calls.

The above example shows the case where time slots are allocated and canceled in response to request signals from exchanges. However, if it is possible to predict the number of time slots that will be allocated to connect exchanges, the processing unit PR will It is also possible to allocate slots in a semi-fixed manner between exchanges by sending a slot assignment signal to the exchanges. For example, exchange EX1 and exchange EX2
If it is foreseen that the slot will always be requested by the slot, slot number 1 of the table memory TM in FIG. 8 is always in use and exchange numbers 1 and 2 are fixed and cannot be rewritten. The processing department PR is
This fixed information is set and stored, and it continues to send assignment signals to both exchanges without waiting for an assignment request signal from exchange EX1 or EX2. If multiple slots are required, fix the multiple slots in the table memory TM in the same way,
It is sufficient to send an assignment signal to the exchange that has assigned multiple slots. This process is also performed by the processing unit PR.

As described above, in the switching device according to the present invention, relay slots can be used in common and can be allocated to the required number of switches, thereby reducing connection blockage between switches and improving connection capacity. This has the effect of making it possible to use relay slots effectively.

In addition, since the control slots are fixed and used between the trunk line management device and multiple exchanges based on semi-fixed line setting conditions, there is no need to select a control slot and the switching speed is high. This has the effect of simplifying the system and equipment.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a conventional switching device, FIG. 2 is a configuration diagram showing a switching device using a ring transmission line,
3 is an explanatory diagram showing the signal format on the ring transmission path of the switching device of FIG. 2, FIG. 4 is a block diagram showing an embodiment of the switching device of the present invention, and FIG. 5 is an explanatory diagram of the switching device of FIG. 6 and 7 are configuration diagrams showing details of the trunk line management device SD and the exchange EX in this switching device, respectively, and FIG. 8 is an explanatory diagram showing the signal format on the ring transmission path. FIG. 3 is an explanatory diagram illustrating the contents of table memory TM. In the figure, 1 is a trunk line, 2 is a ring transmission line, 3 is a signal format on the ring transmission line, EX1, EX2, EX3,
EX4, etc., is an exchange, and SD is a slot allocation device. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a switching device consisting of a trunk line management device, multiple exchanges, and a ring transmission line connecting these,
On the above ring transmission path, there are multiple control slots that are fixedly assigned to each exchange between a trunk line management device for conveying exchange control information using a time division multiplexing method, and multiple exchanges. Frames containing relay slots for carrying shared call signals are circulated, and relay slot assignment request signals, assignment signals, release signals, and The trunk line management device includes a transmitting/receiving unit that receives a relay slot assignment request signal or a release request signal and transmits an assignment signal or a release signal, and a transmitter/receiver that transmits and receives a relay slot assignment request signal or a release request signal, and a transmitter/receiver unit that receives a relay slot assignment request signal or a release request signal and transmits an assignment signal or a release signal; a processing unit that performs processing, cancels the relay slot based on a cancellation request signal, and performs relay slot allocation processing based on semi-fixed line setting conditions; and a table memory for storing the status, and the exchange includes a slot control unit that transmits the allocation request signal or cancellation request signal and receives the allocation signal or cancellation signal, and accesses the allocated relay slot. 1. An exchange device comprising a slot access section and an exchange switch section, and configured to allocate or cancel relay slots.