Colored Petri Net Approach Research Articles

A Coloured Petri Net Approach to Formalising and Analysing the Resource Reservation Protocol


 
 
 The goal of the Resource Reservation Protocol (RSVP) is to support the provision of the Quality of Service required for emerging Internet applications (such as video conferencing) that require a level of performance not guaranteed by the Internet. RSVP attempts to provide performance guarantees by establishing resource reservations (such as the number of buffers and bandwidth allocation) within routers and host computers of the Internet. Currently, Internet protocols are not formally specified when they are developed. Instead they are described in a narrative way in documents called Request for Comments(RFCs). This is the case for RSVP. To increase confidence in RSVP we have formalised and analysed its narrative specification using Coloured Petri Nets (CPNs). This paper demonstrates how CPNs can be used for modelling and analysing RSVP. Among the several beneficial features of CPNs are: graphical facilities for specification; support for different levels of abstraction; hierarchical structuring mechanisms; and verification and validation methods, such as querying the state space to investigate properties, and language equivalence to check the consistency of different levels of abstraction. Coloured Petri Nets are supported by a number of computer tools including Design/CPN. Design/CPN supports the construction and maintenance of CPN models and their simulation and analysis using state spaces. These facilities allow us to create a model that provides a clear, unambiguous and precise definition of RSVP, and to analyse the protocol for functional correctness. The paper concentrates on the approach and the tools used in this investigation.
 
 

Celeritas: a coloured Petri net approach to simulation and control of flexible manufacturing systems

Abstract In many areas of computerization today, the capabilities of hardware systems far exceed the sophistication of software systems needed for optimum control. This research is an attempt to advance software control capabilities of flexible manufacturing systems (FMSs). To this end, an FMS controller architecture, called Celeritas, has been designed and a software system conforming to this architecture has been designed and implemented. Celeritas is a generic, data-configurable FMS controller designed using the coloured Petri nets (CP-nets) modelling paradigm augmented with decision support software to provide both FMS simulation and control. Formalisms of the CP-net paradigm provide straightforward representation of both the inherent concurrency and resource conflicts present in such a complex system. Augmentations provide user-defined routines for real-time interfaces to this information which is utilized to provide resource arbitration services among jobs competing for scarce resources and overall ...