Loxcel Geomatics Logo
Apps / Tools
Product Info
Recent News
Contact Us

Monday, 7-Jan-2019 — SMS Data Quality Requires Solving a Jigsaw Puzzle

Canada Cellular Services uses data from (1) proprietary in-house site location databases, (2) files direct from cellular carriers, and (3) monthly snapshots of the Spectrum Management System (SMS) from Innovation, Science and Economic Development Canada (ISED).

We organize each snapshot into site records, which describe the location of cellular sites, and channel records, which describe the emissions from these sites. The graphs below show site and channel counts over the past two years. Some graphs vary significantly and in unexpected ways, suggesting quality issues with ISED's SMS snapshots.

Jigsaw puzzle pieces with one piece separated

Graph of channel counts for Rogers, Telus, Bell from Jan 2018 to Jan 2019 Graph of channel counts for Freedom, Videotron, Eastlink from Jan 2018 to Jan 2019
Graph of site counts for Rogers, Telus, Bell from Jan 2018 to Jan 2019 Graph of site counts for Freedom, Videotron, Eastlink from Jan 2018 to Jan 2019

The top-left graph shows Rogers channel counts (in blue) increasing stably, tracking the expansion of their wireless network. In contrast, Telus and Bell channel counts (in orange and grey) oscillate wildly, indicating quality issues with SMS snapshots.

The top-right graph shows Eastlink channel counts (in grey) increasing stably, tracking the expansion of their wireless network. In contrast, Freedom channel counts (in blue) show only one change, in Sept 2017, suggesting SMS snapshots are not tracking all changes to Freedom's wireless network.

The bottom-left graph shows site counts swinging wildly, indicating quality issues with SMS snapshots. Other issues with SMS snapshots include field values off by orders of magnitude, and site locations off by 100s of meters.

ISED's SMS snapshots should not be used as-is. Each snapshot is like one piece from a jigsaw puzzle, offering an incomplete picture of Canada's cellular landscape. To complete this puzzle, we carefully backfill with historical data, supplement with data directly from cellular carriers, adjust incorrect data values and reposition site locations.


Current     2018     2017     2016     2015     2014     2013     2012