By Topic

The Subscriber-Line Circuit and the Signaling and Tone System for an Experimental Time-Division Exchange Featuring Delta-Modulation Techniques

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Inose, H. ; Dept. of Electronic Engineering, Univ. of Tokyo, Tokyo, Japan ; Yasuda, Y. ; Kawai, Y. ; Takagi, M.

The time-slot mismatch loss will be avoided and the time-slot assignment will be simplified in a time-division exchange system in which the calling and the called subscriber can use independent time slots arbitrarily assigned. Code-modulation techniques make such systems economically realizable, since a tapped magnetostrictive delay line or a shift register can be used to interchange time slots assigned to the calling and called subscribers. A skeletonized experimental model to demonstrate the feasibility of the system has been developed, and its subscriberline circuit and signaling and tone system are described here. The delta-modulation technique is employed for the purpose of simplifying the modulator and demodulator circuitry and of economizing the time slot interchanging device. The modulator circuitry is considerably simplified by using a monostable blocking oscillator to perform combined operation of comparing, switching and locally-decoding. The simplification makes it possible to install a modulator and a demodulator per subscriber. The signaling and tone system is equipped with three modulators which are commonly used by all speech channels. The signal-to-noise ratio of the subscriber-line circuit with 50-kc sampling rate is 30 db at 800 cps which conforms well to the theoretical estimation.

Published in:

Communications Systems, IRE Transactions on  (Volume:10 ,  Issue: 4 )