NCJ Number
25753
Date Published
1974
Length
14 pages
Annotation
REPORTED ARE THE RESULTS OF A PRELIMINARY MOBILE DIGITAL TERMINAL FIELD TESTING PROGRAM TO DETERMINE THE FEASIBILITY AND RELIABILITY OF DIGITAL COMMUNICATIONS WITHIN THE ENVIRONS OF THE CITY.
Abstract
DISCUSSED ARE THE TOPOGRAPHY OF THE CITY OF LOS ANGELES, THE EXISTING CITY RADIO SYSTEM UTILIZED IN TESTING, THE TEST PROCEDURES, THE TEST RESULTS, AND THE HUMAN/ OPERATIONAL FACTORS OF THE SYSTEM. IN THE COMPOSITE OF THE 802 MOBILE-TO-BASE AND 833 BASE-TO-MOBILE TEST LOCATIONS, TOTALLY SUCCESSFUL FULL-SCREEN MESSAGE TRANSMISSIONS WERE ACCOMPLISHED, RESPECTIVELY, TO 93.8 AND 93.7 PER CENT OF THE LOCATIONS. IN ADDITION, APPROXIMIATELY ONE-HALF OF THE ERROR MESSAGES COULD BE CONSIDERED AS USEFUL MESSAGES BECAUSE OF THE HIGH RATIO OF CORRECT DATA TO CORRECTED ERRORS. IT IS CONCLUDED THAT, WITH PROPER NETWORK DESIGN, RELIABLE TWO-WAY DIGITAL RADIO TRANSMISSION BETWEEN BASE AND MOBILE UNITS IS ATTAINABLE IN THE VARIED ENVIRONMENTS IN THE CITY OF LOS ANGELES; THAT THE EXISTING BASE STATION LOCATIONS OWNED BY THE CITY SHOULD SUFFICE FOR DIGITAL RADIO TRANSMISSION LOCATIONS; THAT THERE WAS NO SIGNIFICANT BETWEEN THE VHF AND UHF FREQUENCIES; AND THAT EXISTING 'OFF-THE-SHELF' MOBILE DIGITAL SYSTEMS CAN FUNCTION WITHIN THE CITY ENVIRONMENT AFTER SOME REDESIGNING.