Broadcast Calculus Interpreted in CCS upto Bisimulation

Journal article, 2001

A function M is given that takes any process p in the calculus of broadcasting systems CBS and returns a CCS process M(p) with special actions {hear?, heard!, say?, said!} such that a broadcast of ω by p is matched by the sequence say? τ∗said(ω) by M(p) and a reception of υ by hear(v) τ∗heard!. It is shown that p ∼ M(p), where ∼ is a bisimulation equivalence using the above matches, and that M(p) has no CCS behaviour not covered by ∼. Thus the abstraction of a globally synchronising broadcast can be implemented by sequences of local synchronisations. The criteria of correctness are unusual, and arguably stronger than requiring equivalences to be preserved — the latter does not guarantee that meaning is preserved. Since ∼ is not a native CCS equivalence, it is a matter of dicussion what the result says about Holmer's (CONCUR'93) conjecture, partially proved by Ene and Muntean (FCT'99), that CCS cannot interpret CBS upto preservation of equivalence.