  Emerging network scenarios require the development of solid large-scale
situated systems. Unfortunately, the diffusion/aggregation computational
processes therein often introduce a source of complexity that hampers
predictability of the overall system behaviour. Computational fields have been
introduced to help engineering such systems: they are spatially distributed
data structures designed to adapt their shape to the topology of the underlying
(mobile) network and to the events occurring in it, with notable applications
to pervasive computing, sensor networks, and mobile robots. To assure
behavioural correctness, namely, correspondence of micro-level specification
(single device behaviour) with macro-level behaviour (resulting global spatial
pattern), we investigate the issue of self-stabilisation for computational
fields. We present a tiny, expressive, and type-sound calculus of computational
fields, and define sufficient conditions for self-stabilisation, defined as the
ability to react to changes in the environment finding a new stable state in
finite time. A type-based approach is used to provide a correct checking
procedure for self-stabilisation.
