Single chip large capacity digital time division switching network

Abstract

A single chip large capacitance digital time-devision exchange network consists of series-parallel convertion, parallel-series convertion on the rear of series-parallel convertion compress matrix of data memory unit the front of parallel-series convertion, address comparing module and controlling memory module. The number of data memory unit is reduced to the 1 / n of that of prior art product to realize smooth dilatation from 16KX16K to 128KX128K. The unique address comparing function makes voice conversion delay is less than a frame that n X 64Kb / s exchange delay is fixed as one frame. The advantages are:simple network structure, low power consumption.

Description

technical field [0001] The invention relates to the program-controlled digital switching technology, in particular, how to make the digital time-division switching network realize large-capacity single-board technology. Background technique [0002] At present, the switching network of large-capacity office switches at home and abroad is usually composed of T-S n -T or T-T n -T(n≥1) constitutes a multi-level switching network. There are many inherent problems in this multi-level switching network: such as large size, many nodes, low reliability, time slot blocking in switching, long delay, no Support n×64Kb / s exchange, etc., it is difficult to meet the modern telecommunication application. [0003] Theoretically, many shortcomings of multi-level switching networks can be overcome by single-level T-type switching networks. Therefore, designing a single-T high-capacity switching network with a simple structure has always been the goal pursued by researchers in this field. ...

AI Technical Summary

Problems solved by technology

[0002] At present, the switching network of large-capacity office switches at home and abroad is usually composed of T-S n -T or T-T n -T(n≥1) constitutes a multi-level switching network. There are many inherent problems in this multi-level switching network: such as large size, many nodes, low reliability, time slot blocking in switching, long delay, no Support n×64Kb / s switching, etc., it is difficult to meet modern telecom applications

However, it is impossible to make a large-capacity single-T network with a special-purpose switching chip. There are two main reasons: First, the capacity of a single-chip special-purpose chip is limited by the speed of the internal storage unit, and the capacity cannot be made large. It is very large, and currently the largest capacity is the dedicated switch chip MT90820 produced by MITEL in Canada, and its capacity is only 2K×2K; secondly, the special switch chip is used to "copy T" and the switch matrix is ​​formed by using a serial bus. Although the capacity can be expanded to a certain extent, the number of dedicated switching chips used in this method is n 2 Growth, capacity growth is limited, and the cost is extremely expensive. For example, using the "copy T" method to form an 8K x 8K switching network requires 16 pieces of MT90820 to form a 4 x 4 switching matrix, which has reached the limit of a single board

[0005] For this reason, in recent years, researchers in this field have proposed other schemes to form a large-capacity single-T switching network. Although there are improvements, there are still shortcomings of one kind or another: some cannot support n×64kb / s data exchange ; Some need to cooperate with software to realize non-blocking switching, which greatly sacrifices efficiency, such as the large-capacity digital time-division T-shaped switching network introduced by the Chinese patent application No. 95107865.8; some use the principle of statistical multiplexing and cannot independently form a network , can only be used in switching systems, such as a centralized / distributed high-speed digital T-shaped switching network introduced by Chinese patent application No. 95118474.1

[0006] Later, a method of forming a switching matrix on a parallel bus appeared, which is to form a matrix of data storage units, so that the capacity of the single board is increased to a certain extent, but the number of its data storage units is still in the form of n 2 Growth, the capacity growth will soon reach the limit, generally the maximum is 16K×16K switching capacity, and the PCB board is very large, the cost is high, and the voice switching delay is very large in terms of performance

In addition, due to the large number of components, the reliability is reduced and the power consumption is increased.

[0007] To sum up, there is no single-T switching network that can achieve large capacity on a single board with a small area, and its performance fully meets the requirements of modern telecommunication applications.

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