EDUCATION
SPOTLIGHT
GIS Analysis of Cellular Phone Coverage
Ian Berdusco and Colten Stevenson had no idea that a trip to the store to purchase a new cellular phone would turn into a successful, GIS-based science fair project. At their local cellular phone store, the salesperson told them that they would benefit from purchasing cell phone plan that included a phone with the new 850 MHz frequency. However, the salesperson could only tell them that 850 MHz was better and the students wanted proof for their local area. So, Ian and Colten, both grade eight students at Valley View Public School in Val Caron, Ontario, near Sudbury, decided to do some research for themselves, and developed a very interesting science fair project. The goal of their project was to measure cellular phone strength in the Sudbury area in order to compare the cellular phone coverage of two different frequencies - 850 MHz and 1900 MHz - and determine which phone provides superior coverage. In addition, they wanted to observe features that affect cellular phone reception. Due to the geographic nature of their question, Ian and Colten decided that using GIS would allow them to display and analyze their results in an effective, visually appealing manner. They began learning the basics of ArcView, and explored some of the other technologies they would need to collect their own data including an HP iPAQ, a Garmin 12 Map GPS unit, and two cellular phones, one at each frequency. In addition, they realized that
Colten and Ian collected data in the field on nine different days, travelling throughout the Sudbury area, and visiting 143 stations to record cell phone signal strength.
When the data collected in the field was added to the base map, it was immediately apparent that there were many areas where the students could place calls on the 850 MHz cell phone but not on the 1900 MHz phone.
ArcNorth News Vol. 7 No. 2 2004
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EDUCATION
SPOTLIGHT
they were going to need local base map data to create the maps showing the data collected in their study. “We contacted the Ministry of Northern Development and Mines and asked if we could use their base map data as part of our project,” said Ian Berdusco. “They asked us to enter into a research agreement for the data, and we signed the necessary documents with Minister Rick Bartolucci.” With the base map data in place, they created a layer in ArcView to show the location of the cellular phone towers in the area. Some of the tower locations were provided by Rogers AT&T, and others were collected using GPS. Once they had their base map completed, Ian and Colten began the field data collection portion of the project. They collected readings
using had different numbers of divisions on their scale bars used to measure signal strength. The Sony Ericsson T68i phone (1900 MHz) had five divisions, and the Nokia phone (850 MHz) had seven. To be able to compare the readings from the two phones, they used Microsoft Excel to normalize the signal strength measurements from the two phones to a scale of ten. “When we plotted the normalized results on the map we found that we could easily see the many areas where we could place calls on the Nokia cell phone operating at 850 MHz but not on the Ericsson phone operating at 1900 MHz,” said Ian. “This was especially evident in the northeast and southwest areas of Sudbury.”
At the Northern Ontario ESRI Regional User Conference, Colten and Ian presented Alex Miller with a map from their project. students had assumed that the signal would be strong but found it to be weak. These instances seemed to occur wherever there was diverse topography. This was supported by the digital elevation model and also observed during the field data collection phase of the project. This type of research could be used by many different groups including the cellular phone company, to help them decide where to put their next tower; their competition, to compare their cell phone coverage; search and rescue operations, to see where their cell phones will operate; and people involved in recreational activities (hiking, fishing, camping, golf, etc.), to determine if they can be contacted by cell phone while away from home. Ian and Colten presented the results of their project at the recent Northern Ontario ESRI Regional User Conference in North Bay. The conference attendees were impressed with the work the students had done with GIS. “Their GIS analysis was very well done, and their presentation was terrific,” said Alex Miller, President, ESRI Canada. “I will be proud to show the map that Ian and Colten created to visitors at our office for years to come.”
Find out more about GIS in schools: http://k12.esricanada.com
Next, the students used ArcGIS Spatial Analyst to create grids based on the normalized cell phone signal strength for each phone, to show where the signal was the strongest. They made the grid partially transparent and overlayed the raster on top of the digital elevation model. When they compared the maps for the two phones, it was immediately apparent that there was a much larger geographic area with strong signal strength for the phone Ian and Colten displayed their science fair poster board at the operating at the new 850 Northern Ontario ESRI Regional User Conference where they MHz frequency. So, the presented their project. salesperson was correct the 850 MHz frequency on nine different days, travelling throughout phone has better coverage in the Sudbury area the Sudbury area, and visiting 143 stations to than the 1900 MHz frequency phone. record cell phone signal strength. “When we looked at the signal strength and “We assumed that cell phone signal strength the buffers of the towers we felt confident that would be strong within 6 kilometres of the our assumption that the signal was strong towers so we concentrated on taking readings within 6 kilometres of the towers was good,” at stations outside of the 6 kilometre buffers said Colten. “However, based on the results, around the towers,” said Colten Stevenson. “If we also think that there could be another cell the signal strength on a phone at a particular phone tower in the southwest that we weren't station was low, we also attempted phone calls aware of because there was an area of strong to confirm whether or not the cell phone signal strength where we did not have tower would actually work.” location on our map.” The two cellular phones that the students were In some cases, there were areas where the
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