Standards Development and Analysis.
ITS provides ongoing leadership and technical contributions to international, national, and local telecommunication standards committees such as ITU, TIA, ATIS. ITS experts are regularly called on to interpret and analyze standards and regulations.
Public Safety Communications Interoperability.
ITS works directly with practitioner agencies to improve the intelligibility and interoperability of communication systems. ITS conducts research in the field and in the laboratory to reflect the real environment in which Public Safety operates.
Table Mountain Field Site.
ITS maintains the Table Mountain Field Site north of Boulder, CO, a unique 1,800 acre designated Radio Quiet Zone and radio research facility that is extensively used for research and experimentation both by ITS and by others under cooperative agreements.
Radio Spectrum Measurement Science (RSMS).
The RSMS system is a customized resource for the performance of fundamental theoretical and applied research. The RSMS-4G truck is a state-of-the-art mobile measurement laboratory used to measure spectrum occupancy and analyze interference problems.
Audio and Video Quality Research.
Objective quality-of-service (QoS) measurements for voice and video communications using different coding and transmission schemes taken in ITS’s unique audio-visual laboratories provide government and industry tools and techniques to assess service quality.
Wireless Voice/Data Systems and Emerging Technologies.
ITS assesses telecommunications system components and emerging technologies, evaluates network survivability, and assesses system effectiveness in national security/emergency preparedness, military, and commercial environments.
Radar Interference Effects Tests and Measurements.
ITS acts as a resource to military and civilian agencies to identify sources of radar signal interference through controlled laboratory and field testing. Root cause analysis leads to engineering of proposed solutions shared with industry.
New Report Describes Speech Intelligibility Testing of LTE Codecs
NTIA Technical Report TR-15-520 Speech Codec Intelligibility Testing in Support of Mission-Critical Voice Applications for LTE, by Steve Voran and Andrew Catellier, released September 30, 2015, describes an effort to identify which digital speech and audio technologies are best-suited for mission-critical voice communications over a fourth generation (4G) wireless network using cellular infrastructure. One of the most challenging aspects of public safety communications is maintaining audio quality in the harsh noise environments in which fire fighters, police officers and other first responders operate. ITS has been researching for many years reliable ways to quantitatively evaluate the speech intelligibility of voice communication, both independently and as part of its Public Safety Communications Research (PSCR) partnership with the Department of Commerce’s National Institute of Standards and Technology. This report describes new research designed to quantitatively evaluate the speech intelligibility in various noisy environments associated with a set of codecs for use on cellular networks using Long Term Evolution (LTE)—the technology envisioned for use on the dedicated nationwide public safety broadband network to be deployed by the First Responder Network Authority (FirstNet), an independent authority within NTIA.
The work was conducted in two phases. In the first phase, 83 codecs were tested in 54 noise environments typically encountered by first responders using an objective estimator of speech intelligibility. This analysis identified 28 codec modes and 6 noise environments for subjective testing in Phase 2. In the second phase of testing, 36 current and retired first responders participated in interactive speech intelligibility tests. The tests identified multiple audio codecs for LTE that can deliver speech intelligibility that meets or exceeds minimum acceptable mission-critical requirements in the wide range of environments that fire fighters and other first responders encounter. These tests also confirmed that the speech quality of audio codecs clearly depends on the data rate available for transmission of voice signals. We hope that the detailed results described in this report can inform some of the design decisions required to deploy mission-critical voice applications for LTE and will eventually result in better communications for first responders.