U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

EQUIPMENT SYSTEMS IMPROVEMENT PROGRAM - EQUIPMENT OPTIONS AND COST IN 911 EMERGENCY PHONE SYSTEMS

NCJ Number
19453
Author(s)
ANON
Date Published
1974
Length
199 pages
Annotation
THIS REPORT FOCUSES ON EMERGENCY UNIVERSAL TELEPHONE NUMBER (911) SYSTEM AND EQUIPMENT OPTIONS AVAILABLE OR WHICH COULD BE MADE AVAILABLE, THEIR TYPICAL COSTS, AND THEIR PERFORMANCE.
Abstract
A BASIC PROBLEM OF PRACTICALLY ALL 911 SYSTEMS ARISES BECAUSE TELEPHONE COMPANY WIRE BOUNDARIES OFTEN DO NOT COINCIDE WITH SPECIFIC MUNICIPAL BOUNDARIES AND, CONSEQUENTLY, THERE IS NO WAY TO TELL WHERE THE 911 CALLS ARE TO BE ROUTED. ESSENTIALLY ALL SOLUTIONS TO THIS PROBLEM ARE BASED ON CALLERS' AUTOMATIC NUMBER IDENTIFICATION (ANI) WHICH ENABLES SELECTIVE ROUTING. AN ALTERNATIVE TO SELECTIVE ROUTING IS A TECHNIQUE, REFERRED TO IN THIS DOCUMENT AS SELECTIVE ANSWERING, WHICH IS BASED ON THE IDEA THAT ALL 911 CALLS ARE ROUTED SIMULTANEOUSLY TO THE TWO OR THREE MUNICIPALITIES SERVED BY A SPECIFIC CENTRAL OFFICE; AND ONLY THE PROPER MUNICIPALITY ANSWERS A CALL AUTOMATICALLY BASED ON A COMPUTER REVERSE DIRECTORY LOOK-UP. RELATIVE ADVANTAGES AND DISADVANTAGES OF SELECTIVE ROUTING AND SELECTIVE ANSWERING ARE DISCUSSED. THE CONCEPT OF A CENTRALIZED VOICE/DATA (CVD) SYSTEM IS ALSO DESCRIBED. THE DOCUMENT REPORTS ON A STUDY OF PROBLEMS TELEPHONE COMPANIES FACE IN PROVIDING AUTOMATIC NUMBER IDENTIFICATION (ANI). FINDINGS INCLUDE THE FOLLOWING: (A) APPROXIMATELY 80 PERCENT OF ALL TELEPHONE SUBSCRIBERS PRESENTLY TERMINATE IN CENTRAL OFFICES WHICH ARE ALREADY EQUIPPED WITH ANI FOR ACCOUNTING PURPOSES, (B) CENTRAL OFFICES WHICH DO NOT NOW HAVE ANI ARE IN LOW POPULATION AREAS WHERE ANI AND SELECTIVE ROUTING OF 911 CALLS IS NOT A PRESSING NEED, AND (C) ANI COULD BE PROVIDED TO PUBLIC SAFETY ANSWERING POINTS FAIRLY EASILY AND AT RELATIVELY MODEST COSTS. (AUTHOR ABSTRACT)