Spectrum Engineering
NOTE: These reports are available either on-line in PDF (portable document) format or only as hard-copy. If you would like a copy of a report that is not available electronically, please make note of the document number and submit your request to:
NTIA Office of Spectrum Management
System Engineering and Analysis Division
Tel. (202) 482-2608
Fax (202) 482-4595
e-mail edrocella@ntia.doc.gov
Related content
Intelligibility of the Adaptive Multi-Rate Speech Coder in Emergency-Response Environments
Abstract: This report describes speech intelligibility testing conducted on the Adaptive Multi-Rate (AMR) speech coder in several different environments simulating emergency response conditions and especially fireground conditions. The intelligibility testing protocol was the Modified Rhyme Test (MRT). Conditions included background noises of various types, as well as a mask associated with a self-contained breathing apparatus. Analog FM radio transmission and Project 25 digital radio transmission were also included in the test as reference points.
Free-Field Measurements of the Electrical Properties of Soil Using the Measured Reflection Coefficient at Normal Incidence and Multilayer Analysis
Nicholas DeMinco, Paul M. McKenna, Robert T. Johnk, Chriss A. Hammerschmidt, J. Wayde Allen, Linh P. Vu
Intelligibility of Analog FM and Updated P25 Radio Systems in the Presence of Fireground Noise: Test Plan and Results
Abstract: This report describes a modified rhyme test (MRT) conducted to characterize the behavior of digital and analog communication in the presence of background noise and moderate RF channel degradation. This is done through the use of reference systems to provide a manufacturer-independent perspective on this issue.