An Improved Three-Channel Carrier Telephone System

The N1 Carrier System is a 12‐channel, double‐sideband system for single cable application. It provides low loss, stable, high velocity service for toll and exchange circuits in the range from 15 or 20 miles to 200 miles. Units and sub‐assemblies are miniaturized and arranged on a plug‐in basis. Emphasis has been placed on reduction in cost of components, as well as simplification of manufacturing methods, engineering, installation and maintenance. Economy is achieved by many novel features, principal among which is a built‐in low cost compandor. By compressing and expanding the volume range of speech, the compandor permits much higher tolerance of noise and crosstalk, thereby substantially lowering the cost of both line and terminal facilities. Other important features are self‐contained dialing and supervisory signaling, an individual channel regulator, and automatic equalization through the use of “frequency frogging,” or interchange of high‐ and low‐frequency groups at each repeater.

show abstract

Transmission Aspects of Data Transmission Service Using Private Line Voice Telephone Channels

Mertz¹,

Mitchell²

1957

Bell System Technical Journal

View full text Add to dashboard Cite

An exploration is reported of the possibilities of a moderately fast data transmission system to use private line message facilities. A comparatively conventional system was desired to permit expeditious application. An auxiliary “word start” signal was necessary for the system considered. Transmission characteristics of a number of arrangements were examined. These included several exploratory AM vestigial sideband systems (using a spectrum similar to telephotography), double sideband AM systems, various telegraph and other multichannel systems. It was concluded that the 1600 bits per second usable over the AM vestigial sideband arrangement was about as fast as could be expected with the data system contemplated. This transmission is not as “rugged,” with respect to impulse noise and sudden level changes, as other slower arrangements, but it is expected to be satisfactory. It will require delay correction, and simple methods are considered for carrying this out.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

An Improved Three-Channel Carrier Telephone System

Cited by 6 publications

References 8 publications

Advances in Carrier Telegraph Transmission

Advances in Carrier Telegraph Transmission

The Type N-1 Carrier Telephone System: Objectives and Transmission Features

Transmission Aspects of Data Transmission Service Using Private Line Voice Telephone Channels

Contact Info

Product

Resources

About