A wide-area LTE network must be supplemented with in-building infrastructure in order for first responders to have adequate communications indoors, according to a report by the National Telecommunications and Information Administration’s Institute for Telecommunication Sciences.
Read NTIA Report here [Note this is a large file]:
http://npstc.org/download.jsp?tableId=37&column=217&id=3503&file=NTIA_Technical_Report_TR_15_518_150727.pdf
The report described the results of testing that was done on the University of Colorado at Boulder’s campus by representatives of the Public Safety Communications Research (PSCR) program, which is a joint initiative of NTIA and the National Institute of Standards and Technology.
“Indoor coverage was measured using the PSCR Band 14 LTE outdoor macro network. We also explored methods for improving in-building coverage using a cell on wheels and small cell feeding either discrete antennas or a distributed antenna system,” the 312-page report noted. “The results indicate that the PSCR macro network by itself does not provide complete coverage inside these buildings and that coverage needs to be supplemented with combinations of a small cell deployed indoors and a cell on wheels (COW). The results indicate that significant system in-building performance improvements can be realized using small cells and a COW.”
The research, which was sponsored by the Department of Homeland Security, “not only can be used to help first responders better communicate during emergencies, but it also may help spur innovation in commercial wireless networks also interested in enhancing indoor coverage,” the Commerce Department said in a blog posting.
“We have obtained an extensive set of data for selected LTE parameters. The behavior of these parameters as a function of the in-building coverage configuration is quite complex. More research is clearly needed to further explore performance improvement of in-building public safety LTE systems,” the report said.
“One area that we were not able to cover in this study was the optimal control of handovers between eNBs when multiple elements were used to provide coverage. The tight time constraints of our field tests precluded optimization, but the results demonstrate that simply increasing RF coverage does not necessarily lead to higher data rates,” the report added. “Peak performance requires both adequate coverage and handover optimization. Another area that should be explored is the repeatability and associated uncertainties of in-building measurements.” – Paul Kirby, paul.kirby@wolterskluwer.com