Cellular census: Explorations in urban data collection

Data collection methods, such as surveys by person or phone, can provide detailed information about urban behaviors. Erlang data is a standard measure used by most network operators, accessible source for the analysis of typical GSM networks. Erlang data cannot be linked to an individual subscriber and does not offer the locational specificity of GPS. It is an antenna level measure, which need an algorithm to spread the point data values across the area served. An average Erlang value can be calculated for each pixel at each 15-minute interval, using a 90-day period to minimize the impact of special events on the data set. The data would also assist enormously in understanding how individual and group behavior changes over time and space.