Towards Interaction Protocol Operations for Large Multi-agent Systems

It is widely accepted that role-based modelling is quite adequate in the context of multi-agent systems (MAS) modelling techniques. Unfortunately, very little work has been reported on how to describe the relationships between several role models. Furthermore, many authors agree on that protocols need to be encapsulated into high-level abstractions. The synthesis of role models is an operation presented in the OORAM methodology that allows us to build new role models from others in order to represent the interrelations they have. To the best of our knowledge this operation has to be performed manually at protocol level and works with protocols expressed by means of messages. In this paper, we present two algorithms to extract the protocol of a role from the protocol of a role model and vice versa that automate the synthesis or role models at the protocol level. Furthermore, in order to deal with protocol descriptions in a top down approach both operations work with protocols expressed by means of an abstraction call multi-role interaction (mRI)

Modelling and verifying IEEE Std 11073-20601 session setup using mCRL2

In this paper we advocate that formal verification should bea part of the development of a communication standard;in a short period of time issues areuncovered that have been in the standard for a number of years, and allsubtleties in the correctness of the protocol are understood.We model and verify the session setup protocolthat is part of the IEEE 11073-20601:2008 standard for communication betweenpersonal health devices.We identify a number of issues present in the standards document.Discussion with a member of the standards committee unveiled that most, but notall, of the identified issues are fixed in the IEEE 11073-20601:2010 version ofthe standard.In addition, the correctness of the protocol, including the fixes, is assessed.For this, properties of the session setup protocol are formulated, and usingthe model checker mCRL2 it is verified whether the model satisfies theseproperties.We show that the session setup protocol is flawed, and propose a straightforwardway to fix this issue

Modelling and verifying IEEE Std 11073-20601 session setup using mCRL2

In this paper we advocate that formal verification should be a part of the development of a communication standard; in a short period of time issues are uncovered that have been in the standard for a number of years, and all subtleties in the correctness of the protocol are understood. We model and verify the session setup protocol that is part of the IEEE 11073-20601:2008 standard for communication between personal health devices. We identify a number of issues present in the standards document. Discussion with a member of the standards committee unveiled that most, but not all, of the identified issues are fixed in the IEEE 11073-20601:2010 version of the standard. In addition, the correctness of the protocol, including the fixes, is assessed. For this, properties of the session setup protocol are formulated, and using the model checker mCRL2 it is verified whether the model satisfies these properties. We show that the session setup protocol is flawed, and propose a straightforward way to fix this issue

Conformance relations for distributed testing based on CSP

Copyright @ 2011 Springer Berlin HeidelbergCSP is a well established process algebra that provides comprehensive theoretical and practical support for refinement-based design and verification of systems. Recently, a testing theory for CSP has also been presented. In this paper, we explore the problem of testing from a CSP specification when observations are made by a set of distributed testers. We build on previous work on input-output transition systems, but the use of CSP leads to significant differences, since some of its conformance (refinement) relations consider failures as well as traces. In addition, we allow events to be observed by more than one tester. We show how the CSP notions of refinement can be adapted to distributed testing. We consider two contexts: when the testers are entirely independent and when they can cooperate. Finally, we give some preliminary results on test-case generation and the use of coordination messages. © 2011 IFIP International Federation for Information Processing

Hybrid Multiresolution Simulation & Model Checking: Network-On-Chip Systems

abstract: Designers employ a variety of modeling theories and methodologies to create functional models of discrete network systems. These dynamical models are evaluated using verification and validation techniques throughout incremental design stages. Models created for these systems should directly represent their growing complexity with respect to composition and heterogeneity. Similar to software engineering practices, incremental model design is required for complex system design. As a result, models at early increments are significantly simpler relative to real systems. While experimenting (verification or validation) on models at early increments are computationally less demanding, the results of these experiments are less trustworthy and less rewarding. At any increment of design, a set of tools and technique are required for controlling the complexity of models and experimentation. A complex system such as Network-on-Chip (NoC) may benefit from incremental design stages. Current design methods for NoC rely on multiple models developed using various modeling frameworks. It is useful to develop frameworks that can formalize the relationships among these models. Fine-grain models are derived using their coarse-grain counterparts. Moreover, validation and verification capability at various design stages enabled through disciplined model conversion is very beneficial. In this research, Multiresolution Modeling (MRM) is used for system level design of NoC. MRM aids in creating a family of models at different levels of scale and complexity with well-formed relationships. In addition, a variant of the Discrete Event System Specification (DEVS) formalism is proposed which supports model checking. Hierarchical models of Network-on-Chip components may be created at different resolutions while each model can be validated using discrete-event simulation and verified via state exploration. System property expressions are defined in the DEVS language and developed as Transducers which can be applied seamlessly for model checking and simulation purposes. Multiresolution Modeling with verification and validation capabilities of this framework complement one another. MRM manages the scale and complexity of models which in turn can reduces V&V time and effort and conversely the V&V helps ensure correctness of models at multiple resolutions. This framework is realized through extending the DEVS-Suite simulator and its applicability demonstrated for exemplar NoC models.Dissertation/ThesisDoctoral Dissertation Computer Science 201