Verifying nondeterministic probabilistic channel systems against omega-regular linear-time properties
Lossy channel systems (LCS's) are systems of finite state processes that communicate via unreliable unbounded fifo channels. We introduce NPLCS's, a variant of LCS's where message losses have a probabilistic behavior while the component processes behave nondeterministically, and study the decidability of qualitative verification problems for omega-regular linear-time properties. We show that-in contrast to finite- state Markov decision processes-the satisfaction relation for linear-time formulas depends on the type of schedulers that resolve the nondeterminism. While the qualitative model checking problem for the full class of history-dependent schedulers is undecidable, the same question for finite-memory schedulers can be solved algorithmically. Additionally, some special kinds of reachability, or recurrent reachability, qualitative properties yield decidable verification problems for the full class of schedulers, which-for this restricted class of problems are as powerful as finite-memory schedulers, or even a subclass of them.
lossy channels communication protocols markov decision processes probabilistic models