This polygon shapefile is a representation of the coverage area for 3G mobile communications networks around the world in 2012. The data is created from submissions made directly to Collins Bartholomew or the GSMA from mobile operators, which provide roaming detail for inclusion in the online mapping application known as Collins Mobile Coverage Web. Polygons representing the network coverage have been split into country areas using the country polygons from the Collins World Explorer vector product. Polygons are supplied as multipart, and include any country ISO or FIPS codes where known. The data is supplied with a nominal resolution of approximately 1km on the ground. This map can be used to locate and analyze mobile communications coverage on a global scale. Collins Bartholomew Ltd. (2014). Global 3G Mobile Communications Network Coverage, 2012. Collins Bartholomew Ltd. Available at: http://purl.stanford.edu/db932mv9734 Operators are asked to submit strong (>= -92dBm) and variable (>= -100dBm and < 92dBm) signal strengths as part of their submissions. The data here includes both types but does not make a distinction between the two. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.