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— We present Cognitive Radio (Policy) Language (CoRaL), a new language for expressing policies that govern the behavior of cognitive radios that oppor-tunistically share spectrum. A Policy Reasoner validates radio transmissions to ensure that they are compliant with the spectrum policies. The Policy Reasoner also discovers spectrum sharing opportunities by(More)
Howe's HOL/Nuprl connection is an interesting example of a translation between two fundamentally different logics, namely a typed higher-order logic and a polymorphic extensional type theory. In earlier work we have established a proof-theoretic correctness result of the translation in a way that complements Howe's semantics-based justification and(More)
Given the diierent perspectives from which a complex software system has to be analyzed, the multiplicity of formalisms is in some sense unavoidable. This poses two important technical challenges: how to rigorously meet the need to interrelate formalisms, and how to reduce the duplication of eeort in tool and speciication building across formalisms. These(More)
We propose rewriting logic as a unifying framework for a wide range of Petri nets models. We treat in detail place/transition nets and important extensions of the basic model by individual tokens, test arcs, and time. Based on the idea that " Petri nets are monoids " suggested by Meseguer and Montanari we define a rewriting semantics that maps(More)
PLAN is a language designed for programming active networks, and can more generally be regarded as a model of mobile computation. PLAN generalizes the paradigm of imperative functional programming in an elegant way that allows for recursive, remote function calls, and it provides a clear mechanism for the interaction between host and mobile code. Techniques(More)
— We argue for a policy-based approach to increase spectrum availability. To this extend, we briefly summarize a new language for expressing policies that allow opportunistic spectrum access. A Policy Reasoner that reasons about these policies has can be used with cog-nitive radios to guarantee policy-specified behaviors while allowing spectrum sharing. We(More)