Architectural Specification of Location-aware Systems in Rewriting Logic

The concept of Location Law was recently put forward for the modelling of architectural aspects of distributed and mobile systems that need to be location-aware. These are systems for which communication and access to resources need to be modelled explicitly at the higher architectural levels of design and cannot be relegated to the lower infrastructural levels: components need to know where the components with which they interact reside and execute their computations, and how they themselves move across the distribution network. For instance, financial systems need to be location-aware because banking at a branch, at an ATM or through the internet are not just operationally different: they are subject to different business rules. In this paper, we endow the architectural approach to location-aware systems based on Location Laws with a formal semantics expressed in terms of Meseguer’s Rewriting Logic. As a result, we obtain a formal framework supporting a three-step development method that operates over two complementary architectural dimensions: the traditional coordination aspects that relate to the logical interconnection of system components, and the new location aspects that handle logical distribution and mobility. Rewriting Logic allows us to validate these dimensions separately, then against each other, and finally to superpose them on the run-time configuration of the system.