ACKNOWLEDGMENTS

This report was prepared by the Law Enforcement Standards. Laboratory of the National Bureau of Standards under the direction of Marshall J. Treado, Program Manager for Communications Systems, and Jacob J. Diamond, Chief of LESL. The principal investigator on this project was John Furze of Urban Sciences, Inc. The assistance and cooperation of the personnel of Allegheny County, Pennsylvania, is deeply appreciated.

NBS Special
Publication
480-19

Digital Data
Transmission
Tests on
Voice Channels

Issued July 1977

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary
Dr. Sidney Harman, Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology
NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

GENERAL BOOKBINDING CO.

Library of Congress Catalog Number: 77-6 000 23
National Bureau of Standards

Special Publication 480-19

Nat. Bur. Stand. (U.S.), Spec. Publ. 480-19, 63 pages
CODEN:XNBSAV

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON:

For sale by the Superintendent of Documents,

U.S. Government Printing Office, Washington, D.C. 20402

(Order by SD Catalog No. C13.10:480-19). Stock No. 003-01773-6 Price $2.10 (Add 25 percent additional for other than U.S. mailing).

!

FOREWORD

The Law Enforcement Standards Laboratory (LESL) of the National Bureau of Standards (NBS) furnishes technical support to the National Institute of Law Enforcement and Criminal Justice (NILECJ) program to strengthen law enforcement and criminal justice in the United States. LESL's function is to conduct research that will assist law enforcement and criminal justice agencies in the selection and procurement of quality equipment.

LESL is: (1) Subjecting existing equipment to laboratory testing and evaluation and (2) conducting research leading to the development of several series of documents, including national voluntary equipment standards, user guidelines, state-of-the-art surveys, and other reports.

This document is a law enforcement equipment report developed by LESL under the sponsorship of NILECJ. Additional reports as well as other documents are being issued under the LESL program in the areas of protective equipment, communications equipment, security systems, weapons, emergency equipment, investigative aids, vehicles, and clothing.

Technical comments and suggestions concerning the subject matter of this report are invited from all interested parties. Comments should be addressed to the Law Enforcement Standards Laboratory, National Bureau of Standards, Washington, D.C. 20234.

Jacob J. Diamond, Chief
Law Enforcement Standards
Laboratory