This raster dataset is a representation of the coverage area for 3G mobile communications networks around the world. Mobile Coverage is released annually in January each year. This data release is named 2018. Any operator data received up to the end of the year 2017 is included in this release. The coverages have been sourced directly from the network operators. However, not every operator has submitted data and so there are inevitable gaps in coverage. 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. The cell values in the MCE rasters are as follows: 1 – strong signal strength 2 – variable signal strength.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. This map can be used to locate and analyze mobile communications coverage on a global scale. Collins Bartholomew Ltd.. (2021). Global 3G Mobile Coverage Explorer, 2018. Collins Bartholomew Ltd.. Available at: http://purl.stanford.edu/sm584bx7151 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.