Signals Research Group (SRG) traveled to Indianapolis on three separate occasions over the last nine months and found that yes, Licensed Assisted Access (LAA) certainly does make a difference in an operator’s network, namely, in this case, AT&T’s network.
The analyst firm was first in Indianapolis in May 2017 to test AT&T’s macro network in the downtown area. SRG returned in September to test the network after the operator deployed some small cells, and its report from that visit showed how the introduction of the small cells had a meaningful impact on spectral efficiency.
Still, something was missing, and when they returned in January 2018, AT&T had substantially built out its small cell network there, including the deployment of LAA. “We documented a substantial impact on network performance—this time benefiting both the operator and the consumer,” SRG wrote in a special preview edition of its Signals Ahead research.
The analyst firm observed a peak data rate of at least 795.1 Mbps based on 1 ms parsing of the data. They also observed at least 43 small cells, primarily in Band 2, with LAA (3 component carriers), and nine different 5 GHz radio channels used by LAA in the UNII-1 and UNII-3 bands, including Channel 165. More than 60% of transferred data occurred with unlicensed spectrum, and all of these data were collected in -10 degrees F windchill.
Accuver Americas provided SRF with its XCAL-Solo drive test tool and XCAP post-processing software. The firm used FTP downlink full buffer (1.6 Gbps FTP server) and various user experience tests (Google Play, Google Drive, etc.) to generate data traffic while walking and driving around the downtown Indianapolis area.
Interestingly, the study used the Samsung Galaxy Note 8, which resulted in an unfortunate “thermal issue,” but not the kind one might assume, the analyst firm said. At one point in the experimentation, the smartphone displayed a warning label saying the phone’s temperature was too low and that charging would resume when the temp gets back to normal.
Back in November, AT&T said it had rolled out commercial LAA technologies in select parts of downtown Indianapolis, with plans to expand LAA in more areas of the downtown by the end of the year. It marked AT&T’s first commercial deployment of LAA, which is considered a key enabler for operators to offer Gigabit-class speeds and a stepping stone to 5G.
Indianapolis also is one of AT&T’s “5G Evolution” markets where it’s offering 256 QAM, 4x4 MIMO and 3-way carrier aggregation. SRG said it doesn’t endorse the use of the “5G Evolution” term, but it’s evident that the physical location and density of the small cell grid set the stage for 5G New Radio (NR) millimeter wave capabilities in the coming years.
“Modest upgrades—largely transparent to the human eye—will enable the existing locations where the small cells are located to support millimeter wave directional antennas,” SRG said. “Further, the current centralized RAN with dark fiber fronthaul will evolve to enable 5G/LTE baseband pooling and eventually a virtualized Radio Access Network (RAN).”