700 MHz In-Building Coverage App & Measurement System Development

Summary

The Public Safety Communications Research (PSCR) program is researching the development of in-building apps for RF coverage evaluation, which is critical for enhancing in-building coverage for public safety. The apps will turn a representative public safety device into an in-building measurement system and coverage evaluation system. The development of easy-to-use apps will enable the rapid collection and post processing of in-building data to assess RF coverage. This project will explore the possibility of public safety professionals doing their own measurements of Band-14 Long Term Evolution (LTE) coverage within or around any building in their jurisdictions and enable the quick identification of problem areas that will need coverage mitigation. Both first responders and the public will benefit through the identification of in-building coverage problems and enabling the mitigation of RF coverage problems.

Description

During the period of 2013-2014, PSCR researchers performed investigations of Band-14 LTE in-building coverage at selected sites on the campus of the University of Colorado. PSCR performed extensive sets of measurements, obtained valuable information and insight about in-building coverage issues, and investigated methods for the mitigation of low RF levels that can occur indoors. 
PSCR engineers utilized specialized measurement equipment that required a high level of operator training to collect and post-process in-building data. The approach had two primary drawbacks. First, PSCR simply does not have either the personnel or the resources to engage in a nation-wide measurement campaign on a large number of buildings. Second, both the equipment and the post-processing software used for this work are expensive and require a high level of operator training and expertise. Clearly, a different approach is needed to make in-building measurements and indoor coverage evaluations more accessible to public safety.

AN INNOVATIVE APPROACH

PSCR will develop a proof-of-concept measurement system that will explore the possibility of public safety professionals doing their own Band-14 coverage measurements for any building. This system will be simple to operate and will provide immediate estimates of in-building coverage. PSCR will develop simple-to-operate software apps that will be installed on a representative Band-14 LTE phone or tablet, similar to devices that will be used by the public safety community for communications over the FirstNet LTE network. Additional apps will be developed and used to provide estimates of the quality of in-building coverage.

VALUE TO PUBLIC SAFETY

This project will demonstrate the possibility of public safety professionals doing their own Band-14 LTE coverage measurements and evaluations within or around any building in their jurisdictions to quickly identify problem areas that will need coverage mitigation. Safety benefits to both first responders and the public will be realized through the identification of in-building coverage problems within their own jurisdictions. This project will empower public safety professionals to proactively fix in-building communications to provide reliable, high-quality communications during emergencies.

Band-14 LTE reference signal received power (RSRP) from the PSCR Band 14 macro network inside the stadium at the Coors Events Center.

Distributions of Band-14 reference signal received power (RSRP) levels (RSRP) for progressively increasing coverage levels.