Timed Protocol Veri cation for Estelle-Speci ed Protocols

This paper presents a new model, which is named Timed Communicating State Machine (TCSM), for specifying protocols that incorporate timed properties as part of their speci cations. The TCSM model is similar to the Extended Communicating Finite State Machine (ECFSM) model. The major extension is providing an additional mechanism, i.e., a time interval attribute, for describing the timed properties. We also propose the corresponding formal TCSM-based timed veri cation scheme, i.e., a new timed global state reachability analysis. In the new timed global state reachability analysis, the exploration is decided by the predicate, the time relationships, and/or the input event. Using the TCSM model and the timed veri cation scheme, an Estelle-based Timed Protocol Veri cation System (ETPVS) has been developed on SUN SPARC workstations. In this way, timed protocols can be formally speci ed in Estelle and can also be veri ed using ETPVS.