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Multistage Space Division Pulse Modulation Switching Matrix Design

IP.com Disclosure Number: IPCOM000085123D
Original Publication Date: 1976-Feb-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 4 page(s) / 107K

Publishing Venue

IBM

Related People

Fisk, DE: AUTHOR

Abstract

This switching matrix arrangement combines space division and time division multiplexing arrangements, for greatly reducing the number of electric switches required for a very large number of communication line interconnections.

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Multistage Space Division Pulse Modulation Switching Matrix Design

This switching matrix arrangement combines space division and time division multiplexing arrangements, for greatly reducing the number of electric switches required for a very large number of communication line interconnections.

In a conventional pulse amplitude modulated (PAM) switching matrix, the number of electric switches that can be attached to a common node is limited by the speed of switching and by the capacitive loading that develops about the node as more and more switches are added.

More complex arrangements have been devised that increase the maximum matrix size possible, but for each technology there is an upper limit to the number of communication lines a matrix can support.

This pulse modulation space (PMS) switching matrix comprises modular blocks that can be structured to have no block larger than the technology design limits, and at the same time provide switching among an arbitrarily large number of communication lines. The savings in the total number of switches in comparison to a comparable space division switch matrix will depend on the pulse modulation technology design limits.

Pulse modulation (PM) as used herein is construed to include pulse amplitude modulation (PAM), pulse code modulation (PCM), pulse duration modulation (PDM), pulse frequency modulation (PFM), pulse interval modulation (PIM), pulse position modulation or pulse phase modulation (PPM), quantizing pulse modulation (QPM), pulse rate modulation (PRM), pulse time modulation (PRM), pulse width modulation (PWM), and retrospective pulse modulation (RPM).

For a switch matrix having 36 inputs and 36 outputs and PM technology that will support no more than 6 inputs and 6 outputs, two modular blocks, a space division multiplexing block with 6 inputs and 11 outputs and a PM block with 6 inputs and 6 outputs are connected, as shown in Fig. 1, to provide a network containing a total of 924 switches. This same matrix, composed entirely of space division blocks, would require 1188 switches. In this example the difference is not startling, but for the PM technology that it can handle 12 inputs and 12 outputs. As shown in Fig. 2 the same switch matrix now c...