Using Viewshed Analysis to Estimate Cellular Coverage
+ 3 Proposed Options to Improve Coverage
Tools: ArcGIS Pro
Data Sources: USGS, U.S. National Park Service, Natural Earth, County of Los Angeles, UCLA GEOG XL 181B Course Website (T-Mobile cell tower points)
April 2022
T-Mobile Cellular Coverage in Los Angeles County
T-Mobile is currently the third largest cellular service provider in the United States. The company has 105 cell towers operating in Los Angeles County, California, which can each provide a maximum transmission radius of 25 kilometers with line-of-sight service. It is estimated that the current T-Mobile service area in Los Angeles County covers approximately 5,266 km2, or 2,003 mi2, which is 42.8% of the county area. The regions with the highest coverage are located in the central urban areas of the City of Los Angeles. Lower coverage areas are found in the northern half of the county, with little-to-no coverage in the mountainous regions that form much of the border of the City of Los Angeles.
At present, three options are available to increase the T-Mobile service coverage in Los Angeles County:
1. Increasing the height of all existing cell towers by 10 meters
2. Increasing the maximum range of all existing cell towers by 5 kilometers
3. Adding 3 new cell towers in underserved areas (Height: 30 meters)
The estimated results of each of these proposed improvements were analyzed to determine which outcome would allow for the greatest increase in service area. It was determined that option three, adding 3 new cellular towers, would be the most effective at increasing service area in Los Angeles County. The table below shows how each approach would affect the cellular coverage of LA County.
Of the three available options, increasing the height of existing towers offered the least improvement. Only very small, scattered areas of coverage were added along the fringes of the existing service area. Increasing the maximum range of existing towers was more effective and, most notably, added a decent coverage area to the northeast portion of the county. However, choosing to build three new cell towers offers the most flexibility and therefore allows for the most effective increase in cellular coverage area.
Many of the low-coverage, mountainous regions of Los Angeles County are within either National Forests or National and State Parks. By avoiding building cell towers in these areas, the remaining underserved areas of the county are the far northeast, far northwest, and the area around the city of Santa Clarita. It is proposed that one cell tower be added to each of these regions, which would increase the T-Mobile service area in Los Angeles County by almost 1,000 km2. Tower sites of appropriately high elevation were chosen in each region in an attempt to maximize the effective service area within each 25 km radius. In the future, further improvements could be made by building additional towers in the Santa Clarita area. This is a populous area that remains a challenging location to provide thorough cellular service due to the moderate mountainous terrain throughout the area. Coverage in the northeast corner of the county could also benefit from one additional tower or by building a tower with an extended range.
