  We propose a graph-based process calculus for modeling and reasoning about
wireless networks with local broadcasts. Graphs are used at syntactical level
to describe the topological structures of networks. This calculus is equipped
with a reduction semantics and a labelled transition semantics. The former is
used to define weak barbed congruence. The latter is used to define a
parameterized weak bisimulation emphasizing locations and local broadcasts. We
prove that weak bisimilarity implies weak barbed congruence. The potential
applications are illustrated by some examples and two case studies.
