RU2458383C1 - Time-spatial switching method - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: when switching timing channels, a computer selects free timing channels of incoming and outgoing communication lines which need switching and writes the address of the channels of the outgoing lines into memory cells belonging to channels of incoming communication lines. Intermediate paths of the digital switching system under investigation are not selected in advance, which significantly reduces the load on the computer.

EFFECT: reduced load on the computer by eliminating the process of searching for free time positions of intermediate paths of digital switching systems when establishing connections, simple process of establishing connections and shorter time for said process.

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Description

The invention relates to the field of electrical engineering, namely to wire communication technology, and can be used in the construction of asynchronous digital switching systems.

One of the most important problems arising in the construction of multi-coordinate digital switching systems (CSC) of the space-time type is the choice of switching method. The correct solution to this problem largely determines success in managing the switching system and grouping.

It is known that in the process of establishing a connection at telephone exchanges, two tasks are performed: 1 - finding free intermediate paths of the switching system that provide connection of the lines of the calling and called subscribers; 2 - connection switching between calling and called subscribers.

On decade-step automatic telephone exchanges, switching devices at the search steps (searchers) are involved in both of these tasks. At coordinate exchanges, switching devices (connectors) do not participate in finding free intermediate paths. These devices, receiving signals from control devices, close only conversational circuits.

Synchronous digital switching systems (CSC), based on finding free intermediate paths of the switching system that provide connection of lines of the calling and called subscribers, are most widely used on the current space-time electronic exchanges. In this case, electronic matrices are widely used, which are a logical continuation of the switching systems of coordinate automatic telephone exchanges. On such electronic exchanges, switching devices are passive and do not participate in the search for free intermediate paths. Computers are forced to solve this problem, which is a drawback of such automatic telephone exchanges, especially when their capacity increases, when the number of intermediate paths in the switching system sharply increases, and consequently, the load on the computer. [Directors N.F., Katanovich A.A. Modern systems of intra-ship communication. SPb., Shipbuilding, 2001, S.199-220]. (Prototype).

If we take into account the emerging tendency, on the one hand, to the enlargement of electronic telephone exchanges and a decrease in their number on the telephone network, and on the other hand, to a significant increase in the number of additional types of services, it becomes obvious that the load placed on the control computer is obvious. [Gonson G. Donglas No. 4 ESS - Lond Distance for Future. - Bell Lab. Rec., 1973, v 51. No. 8]. Under these conditions, the problem of developing new methods of switching is very acute, when using which switching elements, like switching devices of decade-step automatic telephone exchanges, would participate in solving the two above problems. Such switching elements would be active, i.e. seekers, which would reduce the load on the computer.

The aim of the invention is to reduce the load on the computer by eliminating the process of searching for free temporary positions of the intermediate paths of the CSC during the establishment of connections, as well as simplifying the process of establishing connections and reducing its time.

This goal is achieved in that they search for free intermediate paths of the switching system that provide the connection of the lines of the calling and called subscriber, while the control signals in binary code accompany the corresponding switched telephone signals in the process of their transmission along the intermediate paths of the CSK from the moment of receipt of incoming communication lines from temporary channels until they are issued to the temporary channels of the outgoing communication lines, and at the input of the CSK to each switched telephone signal they connect with the corresponding signal in the form of a binary code that accompanies this switched signal and determines the intermediate path of the CSK at each link of the spatial switching stage, while the switched signals consist of sequences of multi-bit words containing the control and information parts, and the control (address) part is a binary control code signal, and information - the binary code of the switched telephone signal, and the addresses of temporary channels and outgoing communication lines.

The drawing shows a structural diagram of a method of space-time switching.

The circuit contains time channel 1 counters (SChVK), intermediate storage registers for these signals 2 (Pr P), address memory block 3 cells (BPA), asynchronous spatial switch 4 (AIC); decoder 5 (DS), buffer memory block 6 (BBP); information memory unit 7 (BPI); information schemes 8 (I); information memory unit 9 (BPI).

In the cells of the address memory block 3, addresses A of the temporary channels of the outgoing communication lines (control signals) are stored. These memory cells belong to the temporary channels of the incoming communication lines, and the cell and channel numbers are the same.

In the process of switching temporary channels, the computer selects the free temporary channels of the incoming and outgoing communication lines, which must be switched between each other, and writes the addresses of the channels of the outgoing lines into memory cells 3 belonging to the channels of the incoming communication lines. Moreover, the intermediate paths of the considered CSK are not preselected, which significantly reduces the load on the computer.

Using the registers 2, the information And arriving at the CSK inputs is converted into a parallel code and fed to the input of the asynchronous spatial switch 4. The addresses of the incoming channels through which the information was received are supplied from the time channel 1 counters to the BPA 3, which in turn provide transformation (replacement) of incoming addresses to outgoing. New addresses arrive at the input circuits AND 8 and LH 5 of the spatial switching level. Outgoing addresses are accompanied from BPA 3 by the signal α = 1, which is recorded in BPA 3 when switching time channels and using DS 5 provides the generation of signals γ _i (i = 1, 2, ..., m) that record information in the corresponding blocks of the buffer memory BBP 6 of the AIC device 4. When disconnecting temporary channels in the BPA 3, the signal α = 0 is recorded, which prohibits DS 5 switching of signals in the AIC 4. Spatial switching provides using DS 5, which selects the required output lines of the outgoing directions of APK 4, and using BBP 6, suschestvlyayuschih allocation information in the free time positions AIC output lines 4. Thus, in an asynchronous APK4 CSK is an active functional unit (finder) and is involved in resolving the two problems of switching the switching devices like step-by-step telephone exchanges.

The transmission of information along highways is carried out by a parallel code and is synchronized by the clock signals (pulses) of the station generator. The transmission of switched signals inside the AIC 4 is carried out using clock pulses τ _i at a speed m times the speed of the transmission line. From BBP 6 AIC 4, the switched signals are sent to the BPI 9 information memory blocks and, using the addresses of the temporary channels accompanying these signals, are recorded in their BPI 9 memory cells. In addition, each outgoing communication channel has its own memory in BPI 9. memory cells and time channels are the same. Further, in accordance with the cycle of operation of outgoing communication lines, switched signals are read from BPI 9 and issued to their temporary channels of outgoing lines.

Asynchronism in the spatio-temporal switching of telephone signals consists in the fact that the information delay time in BBP 6 can only change by one clock cycle of one of the output lines of the AIC 4. In this case, the switched signals transmitted at the i-th time position (interval) will be transmitted after establishing a new connection at the (i + 1) -th time position.

Thus, the proposed method of spatio-temporal switching of PCM signals allows to reduce the load on the computer by establishing the process of searching for free temporary positions of the intermediate paths of the CSK when establishing connections; reduce the amount of computer memory, as it eliminates the need to store employment tables of temporary positions of the intermediate paths of the CSC; Simplify the process of establishing connections and reduce its time. Such methods are also effective in switching signals without external computer control.

Claims (1)

A space-time switching method based on finding free intermediate paths of a switching system providing connection of lines of a calling and a called subscriber, characterized in that the control signals in binary code accompany the corresponding switched telephone signals in the process of their transmission along the intermediate paths of the digital switching system from the moment they arrive from temporary channels of incoming communication lines until they are issued to temporary channels of outgoing communication lines, and at the input of qi In the case of a switching system, a corresponding binary code signal is attached to each switched telephone signal, accompanying this switched signal and determining the intermediate path of the digital switching system at each link of the spatial switching stage, while the switched signals consist of sequences of multi-bit words containing control and information parts, moreover, the control (address) part is a binary code of the control signal, and the information is binary od dial telephone signal and control signals as addresses used outgoing time channels of communication lines.