Mobile instant messaging (MIM) systems have
provided very convenient ways for communication and information
exchange in recent years. Interesting features of these
applications have made them important platforms for spreading
information, idea, behavior, and rumor. In contrast to traditional
social networks, communication in MIM applications is
not necessarily based on friendship relations. In group-based
communication and broadcasting in channels that are prominent
features of MIM systems, users may send messages to and receive
messages from people with whom do not already have friendly
relations. This kind of communication leads to the creation of
special network in which not only users and their contact lists
but also groups and channels are involved. Existing complex
network models are not sufficiently expressive to represent this
kind of communication network. In this article, we introduce
the concept of social communication network (SCN) to be
able to consider special structural properties of communications
in MIM systems and propose a model for representing and
generating the SCN in MIM systems. The proposed model
covers all social communications between users, groups, and
channels and exhibits the statistics observed in real-world data.
We also redefine some existing properties and introduce some
new properties of the MIM network that earlier models of
complex networks do not capture. To evaluate the proposed
model, we conduct a number of simulation experiments on the
model and compare the results with a real-world graph that
we have extracted from Telegram. The results show that SCN
derived by the model is highly compatible with the real-world
graph. The proposed model provides a useful basis for analysis
and evaluation of MIM network properties.