  This article deals with stability of continuous-time switched linear systems
under constrained switching. Given a family of linear systems, possibly
containing unstable dynamics, we characterize a new class of switching signals
under which the switched linear system generated by it and the family of
systems is globally asymptotically stable. Our characterization of such
stabilizing switching signals involves the asymptotic frequency of switching,
the asymptotic fraction of activation of the constituent systems, and the
asymptotic densities of admissible transitions among them. Our techniques
employ multiple Lyapunov-like functions, and extend preceding results both in
scope and applicability.
