  Mobile phone calling is one of the most widely used communication methods in
modern society. The records of calls among mobile phone users provide us a
valuable proxy for the understanding of human communication patterns embedded
in social networks. Mobile phone users call each other forming a directed
calling network. If only reciprocal calls are considered, we obtain an
undirected mutual calling network. The preferential communication behavior
between two connected users can be statistically tested and it results in two
Bonferroni networks with statistically validated edges. We perform a
comparative analysis of the statistical properties of these four networks,
which are constructed from the calling records of more than nine million
individuals in Shanghai over a period of 110 days. We find that these networks
share many common structural properties and also exhibit idiosyncratic features
when compared with previously studied large mobile calling networks. The
empirical findings provide us an intriguing picture of a representative large
social network that might shed new lights on the modelling of large social
networks.
